Remember that successfully completing a root cause troubleshooting is not black magic reserved for experienced professional mechanics, but is determined by a combination of specific knowledge and a patient, systematic approach to investigating the problem. You should always move from simple to complex, bring each check to its logical conclusion and try not to miss obvious facts - anyone can forget to fill the fuel tank or leave lights on at night.
Finally, you should always try to get a clear picture of the development of the malfunction and take appropriate steps to prevent recurrence. If the failure of the electrical equipment occurred due to a violation of the quality of the contact, check at the same time the condition of all other contacts and electrical connectors of the system. If the same fuse continues to blow several times in a row, there is no point in replacing it further - you must try to find out the cause of the failure. Remember that the failure of a minor component may be a sign of a malfunction of a more important node or the entire system.
Diagnostics of electronic systems E46 - general information about diagnostic devices
Vehicle electronics include:
- Siemens MS 42.0 petrol engine electronic control system
- Bosch 3.0 Diesel Electronic Control System
- ABS anti-lock brake system
- dynamic stability control system built into ABS - DSC3 on early E46 models traction control - (Teves ABS/ASC Mark20ET)
- Additional security system SRS, MRS2, MRS3
- АТ with electronic control EGS/AGS, A5S 360R Siemens AGS 20
Electronic xenon headlight system
1. Checking the correct functioning of the components of the injection systems and reducing the toxicity of exhaust gases is carried out using a universal digital meter (multimeter). The use of a digital meter is preferred for several reasons. Firstly, it is quite difficult for analog devices to (sometimes impossible), to determine the result of the indication with an accuracy of hundredths and thousandths, while when examining circuits that include electronic components, such accuracy is of particular importance.
The second, no less important, reason is the fact that the internal circuit of a digital multimeter has a fairly high impedance (the internal resistance of the device is 10 mΩ). Since the voltmeter is connected in parallel to the circuit under test, the measurement accuracy is higher, the smaller the current will pass through the device itself. This factor is not significant when measuring relatively high voltage values (9 ÷12 V), however, it becomes decisive in the diagnosis of elements that produce low-voltage signals, such as, for example, an l-probe, where it is a question of measuring fractions of a volt.
2. Special diagnostic scanners are used to diagnose electronic systems of the engine, automatic transmission, ABS, SRS (Pointer) or testers (Retriever) with specific cartridge, universal cable and connector. In addition, for this purpose, you can use an expensive specialized automotive diagnostic computer, specially designed for the complete diagnosis of most systems of modern cars (e.g. ADC2000 from Launch HiTech), or a regular computer with a set of interface devices.
3. In principle, reading the fault codes stored in the memory of the self-diagnosis system can also be done using the indicator "check engine" on the dashboard (contact the head Engine electrical equipment).
4. The scanner only reads the entered fault memory and clears the fault memory. In addition, the scanner only supports the ISO protocol. The tester can additionally activate and display current data and supports SAE and ISO protocols.
All tester cartridges can also be used in the scanner. In this case, the functions will be limited to only reading and clearing memory.
For diagnostics, for example, devices from ToolRama, Inc. can be used. (3500 NW Boca Raton Blvd., Boca Raton, Florida, 33431, USA 1 877 866 5726 – 561 750 4511 – 561 338 8447 FAX):
- R000 tester with T051D cartridge, P000 scanner with T041 cartridge,
- universal cable N000,
- connector N001.
For most vehicles manufactured since 1996 that support the SAE/ISO 9141 OBD II protocol, an OBD II cartridge can be used that performs the following functions:
- Reading and clearing OBD II trouble codes. Displays oxygen sensor test results.
- Continuous monitoring of ignition, injection and component systems.
- Displaying a list of current data and fixed transient failures:
- Absolute pressure in the inlet pipeline;
- Oxygen sensor voltage;
- Engine coolant temperature;
- Estimated engine load;
- vehicle speed;
- fuel quality;
- Air flow (by weight);
- Ignition advance;
- Throttle position;
- Intake air temperature.
In addition to trouble codes "P0 ", the instrument also displays extended codes "P1 " for models Acura, Audi, BMW, Chrysler, Dodge, FORD, Geo, GM, Honda, Hyundai, Infinity, Kia, Lexus, Lincoln, Mercury, Mazda, Mercedes, Mitsubishi, Nissan, Porsche, Saturn, Seat, Skoda, Subaru, Suzuki, Toyota, Volvo, VW.
Recently, reading devices such as hand-held scanners such as Actron Scantool or AutoXray XP240 have become absolutely indispensable in the diagnosis of engine control systems of modern cars.
Features of ADC2000 specialized automotive diagnostic tool:
- Built-in 4-channel oscilloscope with standard preset for 19 probes.
- Ignition analyzer for testing primary and secondary circuits (with voltage up to 100 kV) on systems with a distributor or separate ignition coils - with control of burning time, peak voltage, ignition timing, current, and revolutions.
- Two-channel multimeter with digital and graphical representation of voltage data (150V), frequency (1100kHz), current (150A).
- Built-in scanner for the main systems on cars: VAG, MB, BMW, Volvo, Toyota / Lexus, Mitsubishi, Nissan, Honda, Mazda, GM, Ford, Chrysler, Daewoo, Hyundai, Kia, Samsung, as well as on cars that support the protocol OBDII.
- Cartridges are not required - you can update the device programs yourself by downloading the necessary updates from the Internet.
- Software for communication with a personal computer.
Information on the use of these devices is contained in the enclosed documents. You can find more information about these devices on the websites programatools.com, lasn.com.
For diagnostics, we recommend that you seek qualified help from service station specialists.
The OBD II diagnostic connector is located under the instrument panel.
Diagnostic connector contacts for the protocols used:
- ISO 9141-2 Pins 4, 5, 7, 15, 16
- J1850 PWM Pins 2, 4, 5, 10, 16
- J1850 VPW Pins 2, 4, 5, 16 (without 10)
ISO 9141-2 protocol (for Europe and Asia) identified by the presence of pin 7 and the absence of pins 2 and/or 10 on the diagnostic connector.
Protocols SAE J1850 VPW (Variable Pulse Width Modulation) – General Motors – or SAE J1850 PWM (Pulse Width Modulation) - American Ford - identified by the absence of contact 7.
All three communication protocols work through a standard OBD-II J1962 cable.
Output No | Purpose |
1. | Set by the manufacturer |
2. | Bus+ line, SAE J1850 |
3. | Set by the manufacturer |
4. | Housing connection |
5. | Housing - signal output |
6. | Set by the manufacturer (CAN high, J-2284) |
7. | Line K, ISO 9141 |
8. | Set by the manufacturer |
9. | Set by the manufacturer |
10. | Bus Line - SAE J1850 |
11. | Set by the manufacturer |
12. | Set by the manufacturer |
13. | Set by the manufacturer |
14. | Set by the manufacturer (CAN Low, J-2284) |
15. | Line L, ISO 9141 |
16. | Plus batteries through the fuse. Energized in any position of the ignition switch |
Fault codes for the OBD II system are given in the Specifications for the Chapter Engine electrical equipment.
The 20-pin BMW diagnostic connector is located under the hood of the engine compartment on the left.
Pin assignment
Characteristic | Meaning |
data | data |
data | data |
data | data |
Engine
If the engine does not start, analyze the situation. For an engine to start at all, two basic conditions must be met. A fuel-air mixture should flow into the cylinders, and a spark should be generated at the spark plug. Therefore, firstly, you should check whether fuel is supplied. How to do this is described in Chapter Power, injection and exhaust systems.
To determine if a spark is being produced, the candles should be unscrewed, inserted into the tips and individually applied to the mass. When doing this, do not hold the tip or ignition cable with your hands, but use well-insulated tongs. Have an assistant start the engine. If the spark does not slip, determine the malfunction according to Chapter Engine electrical equipment.
Engine won't crank when trying to start it
1. The battery terminals are corroded or the wire ends are loose. Check the condition of the terminals and lugs. Tighten the terminal clamps, if necessary, remove traces of corrosion.
2. Discharged or defective battery. If the wire lugs are found clean and securely attached to the battery terminals, turn the ignition key to the ON position, then turn on the headlights and/or windshield wipers. If this electrical equipment does not function, the battery is dead.
3. Transmission is not correctly set in position "R" (AT) or into neutral (RKPP), or the clutch is not fully depressed.
4. The wiring in the starting system circuit is broken or the wires are loose on the terminals. Check the condition of the wires, terminals and electrical connectors of the battery, the starter traction relay and the ignition switch.
5. Starter gear stuck in flywheel ring gear. On models equipped with a manual transmission, put it in gear and, manually pulling it into the car, turn the engine over. At the first opportunity, remove the starter and check the condition of the gear and flywheel ring gear.
6. Defective starter relay (Chapter Engine electrical equipment).
7. Faulty starter (Chapter Engine electrical equipment).
8. Faulty ignition lock.
Engine cranks but won't start
1. Wrong startup
Starting procedure for a gasoline engine:
Apply the parking brake, depress the clutch pedal. On models with АТ press and hold a brake pedal. On AT, set the selector to position "R" or "N". Don't give gas. Turn the ignition key and hold until the engine starts. If the engine does not start within 20 seconds or stops immediately, repeat the starting process with the gas pedal half pressed. As soon as the engine starts, release the ignition key.
In frost below -15°C and at an altitude of more than 1000 m above sea level: Start at least 10 seconds with the pedal half pressed.
Be sure to move on immediately. If it is very cold, let the engine run for 30 seconds.
If the engine does not start after 10 seconds, interrupt the start and repeat it after half a minute.
Several failed start attempts in a row can damage the catalytic converter as unburned fuel combusts explosively when heated in the catalytic converter.
Only on a hot engine after starting, add some gas.
2. Fuse defective:
- Electric fuel pump
- Electronic injection system
For checking fuses, refer to Chapter Onboard electrical equipment.
3. Empty fuel tank.
4. There is a malfunction in the fuel injection system.
5. Low battery (engine cranks too slowly). Check the functioning of the electrical equipment.
6. Battery terminal connections are corroded or loose.
7. Faulty fuel pump (Chapter Power, injection and exhaust systems).
8. Damaged or excessively wet components of the ignition system (Chapter Engine electrical equipment).
9. Worn or defective spark plugs or incorrect spark plug gap (Chapter Engine electrical equipment).
10. Broken or disconnected wiring of the electric circuit of the starting system or loosened fastening of the wires to the terminals.
11. Broken or disconnected ignition coil circuit wiring or loose wires at coil terminals (Chapter Engine electrical equipment).
12. Compression pressure too low. Replace the cylinder head gasket. Repair the engine if necessary.
Diesel engine:
13. Wrong start
Starting procedure for a turbodiesel engine:
On a cold engine and when the outside temperature is below +8°C, apply the parking brake, depress the clutch pedal. On AT, set the selector to position "R" or "N" - RKPP. Turn the ignition key to position II and wait until the preheat indicator lamp goes out. Immediately after the control lamp goes out, start the engine without giving gas. If irregular flashes appear, do not turn off the starter until the engine runs evenly (no more than 30 s). If the engine does not start, repeat starting after half a minute as described above.
In the process of pre-heating the engine, do not turn on current consumers (light, heated rear window).
On a cold engine and at an outside temperature above +8°C, as well as with a warm engine, preheating is not required. The engine can be started immediately. Don't give gas.
14. Fuse defective:
- Electric fuel pump.
- Preheat systems.
15. The engine is not warmed up: check the correct operation of the preheater.
16. There is no voltage at the solenoid shut-off valve. Connect a voltmeter or LED probe to the switch. Turn on the ignition. The LED should light up. Otherwise, you need to find a break in the wiring and fix it.
17. Faulty solenoid shut-off valve. Check the reliability of the fastening of the electromagnetic switch, check the contacts. Turn the ignition on and off. The switch should click.
18. There is damage in the fuel supply line or air in the lines:
- a) Pipelines or hoses are mechanically damaged or clogged. Clean fuel lines and bleed air from lines and filter.
- b) Fuel filter clogged. Replace filter element.
- c) In winter, the filter and piping should be checked for ice or wax. Put the car in a heated garage, add gasoline to the system.
- d) Clogged tank vent or fuel inlet strainer. Clean out.
19. The adjustment of the start of the fuel supply is knocked down. Check, make adjustments.
20. Faulty injectors. Check. Loosen the union nuts one by one - when the nut of the faulty cylinder is unscrewed, the engine speed will not drop.
21. Faulty high pressure fuel pump (injection pump). Install a new or known-good injection pump for testing.
22. Compression pressure too low. Replace the cylinder head gasket. Repair the engine if necessary.
The starter operates without cranking the engine
1. Stuck starter gear. Remove the starter (Chapter Engine electrical equipment) and check its status.
2. Worn or damaged starter gear teeth or flywheel crown.
Difficulty starting a cold engine
1. Discharged or insufficiently charged battery.
2. There is a malfunction of the components of the power system or electrical equipment (Chapters Power, injection and exhaust systems and Engine electrical equipment).
3. Paraffin in the diesel engine fine filter. Replace filter element. Refuel with winter fuel, or dilute with gasoline.
4. Faulty diesel engine glow plugs.
Difficulty starting a hot engine
1. Blocked air filter (Chapter Power, injection and exhaust systems).
2. There is a malfunction of the components of the power system or electrical equipment (Chapters Power, injection and exhaust systems and Engine electrical equipment).
3. Fuel does not reach the injection system injectors (Chapter Power, injection and exhaust systems).
4. The fuel advance angle of the diesel engine has gone astray.
5. Low compression in the cylinders, the injection pump of the diesel engine is faulty or misadjusted.
Starter engagement is too noisy or difficult
1. Worn or damaged starter gear teeth or flywheel crown.
2. Lost starter mounting bolts or loose tightening force.
Engine starts but immediately stalls
1. Faulty wiring or loose wires at the coil or generator terminals.
2. There is a malfunction of the components of the power system or electrical equipment (Chapters Power, injection and exhaust systems and Engine electrical equipment).
3. Vacuum loss occurs through the sealing surfaces of the intake manifold or fuel injection unit. Make sure that the fixing bolts/nuts are securely tightened, check the fact and quality of fastening on your fittings on the inlet pipeline of all vacuum hoses. Check the condition of the hoses and the correct connection (exactly to your fittings).
The stability of the engine at idle is broken
1. There are vacuum losses. Make sure that the fixing bolts/nuts are securely tightened, check the fact and quality of fastening on your fittings on the inlet pipeline of all vacuum hoses. Listen to the running engine with a stethoscope or a piece of fuel hose. The presence of a hissing sound will reveal the source "leaks" vacuum. No less effective can be used for checking a solution of soapy water.
2. There is a malfunction of the components of the power system or electrical equipment (Chapters Power, injection and exhaust systems and Engine electrical equipment).
3. Blocked crankcase ventilation valve (ChapterEngine).
4. Blocked air filter (Chapter Power, injection and exhaust systems).
5. The fuel pump does not supply enough fuel to the injection system injectors (Chapter Power, injection and exhaust systems).
6. There are leaks through the cylinder head gasket. Measure the compression pressure in the engine cylinders.
7. Camshaft lobes worn out (Chapter Engine).
Diesel engine:
8. The quality of the connections of the fuel hoses on the injection pump and the fuel filter is broken. Replace the fuel hoses, secure them with clamps, tighten the corner screws.
9. Mechanically damaged or loose fastening of the injection pump. Check fastening.
10. The connections of the return pipeline and the fuel supply pipeline are reversed. Put connections in place. The return pipe connection screw is marked "OUT".
11. There is damage in the fuel supply line:
- a) Pipelines or hoses are mechanically damaged or clogged. Clear fuel pipelines.
- b) Fuel filter clogged. Replace filter element.
- c) In winter, the filter and piping should be checked for ice or wax. Put the car in a heated garage, add gasoline to the system.
- d) Clogged tank vent or fuel inlet strainer. Clean out.
12. Adjustment of the start of the fuel supply is knocked down. Check, make adjustments.
13. Faulty nozzles. Check. Loosen the union nuts one by one - when the nut of the faulty cylinder is unscrewed, the engine speed will not drop.
14. Faulty high pressure fuel pump (injection pump). Install a new or known-good injection pump for testing.
Misfiring occurs when the engine is idling
1. Worn or dirty spark plugs or incorrect spark plug gap (Chapter Engine electrical equipment).
2. There is a malfunction of the components of the power system or electrical equipment (Chapters Power, injection and exhaust systems and Engine electrical equipment).
3. Faulty spark plug wires (Chapter Engine electrical equipment).
4. There is a loss of vacuum in the intake manifold or through the hose connections.
5. Insufficient or unevenly distributed compression pressure in the cylinders. Take a compression test (Chapter Engine).
Misfiring occurs when vehicle is in gear
1. Blocked fuel filter or contaminated fuel system (Chapter Power, injection and exhaust systems).
2. Faulty or dirty spark plugs or incorrect spark plug gap (Chapter Engine electrical equipment).
3. There is a malfunction of the components of the power system or electrical equipment (Chapters Power, injection and exhaust systems and Engine electrical equipment).
4. There is a defect in the spark plug wires (Chapter Engine electrical equipment).
5. Components of systems of decrease in toxicity of the fulfilled gases are faulty.
6. Insufficient or unevenly distributed compression pressure between the cylinders. Remove spark plugs and measure compression pressure (Chapter Engine).
7. Faulty ignition system (Chapter Engine electrical equipment).
8. Vacuum loss occurs at the throttle body, intake manifold, or through the vacuum hoses.
Engine stalls
1. Idle speed adjustment is broken.
2. Blocked fuel filter and/or moisture or dirt in the fuel system (Chapter Power, injection and exhaust systems).
3. There is a failure of the components of the power system or sensors (Chapter Power, injection and exhaust systems).
4. Components of systems of decrease in toxicity of the fulfilled gases are faulty.
5. Faulty or dirty spark plugs or incorrect spark plug gap (Chapter Ongoing care and maintenance). Also check the condition of the spark plug wires (Chapter Engine electrical equipment).
6. There are vacuum losses at the throttle body or through the vacuum hoses.
The engine does not develop full power
1. There is a malfunction of the components of the power system or electrical equipment (Chapters Power, injection and exhaust systems and Engine electrical equipment).
2. Air cleaner clogged. Clean or replace.
3. Faulty spark plugs or incorrect spark plug gap (Chapter Ongoing care and maintenance).
4. Faulty ignition coil (Chapter Engine electrical equipment).
5. Does not meet the requirements of the liquid level AT (Chapter automatic transmission).
6. Clutch slips (Chapter Clutch and drive shafts).
7. Blocked fuel filter and/or dirt/moisture in the fuel system (Chapter Power, injection and exhaust systems).
8. Wrong grade of fuel filled. Fill the tank with fuel with the required octane rating.
9. Insufficient or uneven compression pressure across the cylinders. Carry out a compression test, the analysis of the results of which reveals the presence of valve leaks and / or a leak in the cylinder head gasket (Chapter Engine).
Optional for diesel engine
10. Clogged air cleaner. Clean or replace
11. Uneven fuel injection pump on the cylinders. Adjust on a warm engine.
12. Incorrectly set the moment of the start of the fuel injection pump. Install.
13. Clogged fuel filter or injection pump (nozzle). Flush pre-filter, change fine filter element, clean sprayer or replace pump (nozzle).
14. The adjustment of the maximum speed of the crankshaft is broken.
There are pops in the intake system or shots in the exhaust system
1. There is a malfunction of the components of the power system or electrical equipment (Chapters Power, injection and exhaust systems and Engine electrical equipment).
2. There is a defect in the secondary circuit of the ignition system (destruction of spark plug insulators or defects in spark plug wires) (Chapter Engine electrical equipment).
3. The fuel injection system needs adjustment or its components are excessively worn (Chapter Power, injection and exhaust systems).
4. There is vacuum loss at the throttle body, intake piping, or through the vacuum hoses.
5. Stuck valves (Chapter Engine).
6. The order of connecting candle wires is violated (Chapter Engine electrical equipment).
Detonation sounds occur when accelerating or going uphill
1. Wrong grade of fuel filled. Fill the tank with fuel with the required octane rating.
2. There is a malfunction of the components of the power system or electrical equipment (Chapters Power, injection and exhaust systems and Engine electrical equipment).
3. Wrong type spark plugs installed. Check spark plugs and coils for damage (Chapter Engine electrical equipment).
4. There are vacuum losses.
There is an ignition (the engine continues to run after the ignition is turned off)
1. Excessively high idle (Chapter Engine).
2. There is a malfunction of the components of the power system or electrical equipment (Chapters Engine electrical equipment).
3. Excessive engine operating temperature. Possible causes of this violation may be a decrease in the coolant level (Chapter Cooling, heating systems), thermostat failure, radiator blockage, or water pump failure (Chapter Cooling, heating systems).
Diesel engine smokes
1. Black smoke:
- a) The air cleaner is dirty. Rinse and refill with fresh oil or replace element.
- b) Wrong fuel used. Flush the tank and change the fuel.
- c) Incorrectly set the moment of the beginning of the supply of high pressure fuel pump.
2. Blue smoke:
- a) Burning oil in the combustion chamber due to wear of the piston rings, high oil level in the air cleaner, wear of the seals in the turbocharger covers, the formation of leaks in the gasket between the crankcase and the turbocharger. Repair the engine, set the correct oil level, replace the oil seals, tighten the turbocharger mounting bolts or replace the gasket.
- b) No fuel is being supplied to one of the injectors. Check for heating of the manifold exhaust pipes.
- c) Poor atomization of fuel by the injector due to a valve malfunction or an atomizer break. Lap the valve or replace the nozzle.
3. White or brown smoke:
- a) Low temperature in the cooling system. Check thermostat.
- b) Poor operation of nozzles due to wear or breakage of the atomizer. Replace atomizer.
Engine electrical equipment
Battery not "keeps" charge
1. The alternator drive belt is worn or damaged, or its tension is not adjusted (Chapter Engine electrical equipment).
2. Insufficient electrolyte level or severely discharged battery (Chapter Engine electrical equipment).
3. The battery terminals are corroded or the wire lugs are loose on them (Chapter Engine electrical equipment).
4. The generator does not provide the required charge current (Chapter Engine electrical equipment).
5. Broken or otherwise damaged charging circuit wiring or loose wires at the terminals (Chapter Engine electrical equipment).
6. A short circuit in the wiring creates a permanent leakage of current generated by the battery to ground (contact the head Engine electrical equipment and electrical equipment diagrams).
7. There is an internal defect in the battery.
The ignition control lamp does not go out when the rpm is increased
1. Loose drive belt. Check the V-belt tensioner.
2. Freewheel damage (only turbodiesel). Remove the generator and turn the generator drive shaft to the left. If the pulley face does not rotate, then the damage is usually in the freewheel.
3. Damage to the voltage regulator / generator. Disconnect the wire (D+) on the back of the generator and turn on the ignition. If now the control lamp does not light up, the fault is usually in the voltage regulator or in the generator.
4. Wear of brushes. Visually check the brushes, replace if necessary.
5. Regulator damage. Check, replace if necessary.
6. Damage to the generator. Check, replace if necessary.
7. Damage to the wire between the generator and the voltage regulator. Disconnect the blue wire at terminal 12 of the T32a connector and at the instrument panel unit. If now the control lamp does not light up, the D+ wire is connected to ground. Replace harness.
8. Damage to the instrument panel block. If, after disconnecting the blue wire from the T32a plug connection with the ignition on, the control lamp lights up, the malfunction is usually in the instrument panel unit.
The ignition control lamp does not light up when the ignition key is turned to "ON" (when the ignition is turned on)
1. Burnt out or otherwise failed control lamp on the instrument panel (Chapter Onboard electrical equipment).
2. Faulty generator (Chapter Engine electrical equipment).
3. There is a defect in the printed circuit board, wiring inside the dashboard unit or lamp socket (Chapter Onboard electrical equipment).
The control lamp of a charge burns after switching off of ignition
1. Positive diodes have a short circuit. Check diodes, replace diode board
Starter
If the starter does not crank, first check that the traction relay terminal 50 has the required voltage of at least 10 V. If the voltage is below this value, check the wires included in the starter current circuit according to the diagram.
Whether the starter engages at full battery voltage can be checked as follows:
- Without switching gears, turn on the ignition.
- Bridge terminals 30 and 50 of the starter with a wire of at least 4 mm section2, refer also to Section Removal, installation and check of the traction relay of a starter.
If the starter works flawlessly, the cause of the malfunction should be sought in the wires to the starter. If the starter does not work, it should be checked in the removed state.
Check condition: At the connection points, the wires must be well fixed and must not be oxidized.
The starter does not rotate when the ignition switch is turned on
1. Low battery. Charge the battery.
2. Bridge terminals 30 and 50 of the starter: The starter turns. Broken wire 50 to the ignition switch, the starter switch is faulty. Repair break, replace defective parts.
3. Breakage of the cable or ground connector, the battery is discharged. Check battery cables and connectors, measure battery voltage, charge if necessary.
4. Insufficient current flow due to loose or oxidized connectors. Clean battery poles and terminals, check connections between battery, starter and ground.
5. There is no voltage at terminal 50 of the traction relay. Broken wire, starter switch defective.
The starter rotates slowly and does not turn the crankshaft
1. Battery discharge. Charge the battery.
2. Filled with summer oil. Fill with multigrade oil.
3. Insufficient current flow due to loose or oxidized connectors. Clean battery poles and terminals, check connections between battery, starter and ground.
4. The carbon brushes are loose on the commutator, stuck in the guides, worn, broken, oily or dirty. Check brushes, clean or replace. Check guides.
5. Insufficient distance between brushes and commutator. Replace brushes and clean brush guides.
6. The collector is grooved or burnt and oily. Treat manifold or replace anchor.
7. No voltage at terminal 50 (min. 8 V). Check the starter switch or traction relay.
8. Broken bearing. Check bearing, replace if necessary.
9. Faulty traction relay. Replace the traction relay.
The starter seizes and rotates the engine jerkily
1. Defective gear drive. Replace gear drive.
2. The gear is dirty. Clean the gear.
3. Faulty flywheel ring gear. Process the ring gear, if necessary, replace the flywheel.
Starter gear does not move away from crown
1. Gear drive or threads are dirty or damaged. Clean or replace gear drive.
2. Faulty traction relay. Replace the traction relay.
3. Return spring is weak or broken. Replace return spring.
The starter continues to work after the ignition key is released
1. The traction relay is stuck, does not turn off. Immediately turn off the ignition, replace the traction relay.
2. The ignition lock does not turn off. Disconnect the battery immediately, replace the ignition switch.
Supply system
Excessive fuel consumption
1. Dirty or blocked air filter element (Chapter Power, injection and exhaust systems).
2. There is a malfunction of the components of the power system or electrical equipment (Chapters Power, injection and exhaust systems and Engine electrical equipment).
3. Insufficient tire pressure or wrong size tires fitted.
diesel engine
4. Clogged return line. Blow out the return line from the injection pump to the fuel tank with air.
5. Too high idle speed and maximum speed. Adjust.
6. The engine has mechanical damage. Check compression, repair engine if necessary
There are fuel leaks and/or a smell of gasoline
1. There are leaks in the fuel lines or vent lines (Chapter Power, injection and exhaust systems).
2. Fuel tank full. Refuel only until the gun automatically shuts off.
3. There are leaks or evaporation from the lines of the power system and reduce the toxicity of exhaust gases (Chapter Power, injection and exhaust systems).
Engine won't start
1. When the starter is turned on, the electric fuel pump does not work (no noise from work). Tap the pump body lightly to loosen the stuck part. Check if voltage is being applied to the pump. Check fuse. Check electrical contacts for good conductivity.
2. Faulty fuel pump relay. Check the relay.
3. Stuck injector valves. Check injectors, replace if necessary. Check the voltage supply to the injectors. To do this, disconnect the injector connector. Attach a diode test lamp to the wire and turn on the starter. The control lamp should flash.
4. There is no signal from the ignition timing sensors or the engine speed sensor. Check electrical wires. Interrogate the fault memory.
5. The position of the AT selector is not displayed on the dashboard, the charge indicator flashes or lights up constantly. Fault code 11 (the oil level sensor-switch is damaged or the fuse 30 at 7.5A is broken) is written to the dashboard memory. Replace fuse or oil level sensor (12 611 433 596).
6. Damaged, clogged or leaking fuel lines, hoses are defective.
7. Clogged fuel filter.
8. Presence of ice or wax in the filter or lines of the diesel engine.
9. Clogged fuel tank ventilation, the filter in the tank is clogged.
10. Diesel engine injectors damaged. Loosen the union nuts one by one and check if the corresponding cylinder works.
Cold engine starts badly, works unstably
1. The content of CO does not meet the requirements. Check CO content and idle speed.
2. Faulty temperature sensor. Check the coolant/intake air temperature sensor.
3. Fuel pressure does not match the required value. Check fuel pressure.
Warm engine starts poorly, runs erratically
Leaky air intake system. Check intake system. To do this, leave the engine idling and cover the seals and connections on the intake tract with gasoline. If the speed increases for a short time, repair leaks.
Engine runs intermittently
1. Electrical connections to the fuel pump are interrupted from time to time. Check the condition of the plug connections and connectors of the electrical wires of the fuel pump, air flow meter and fuel pump relay. Check the fuse and contact points on the fuel pump relay. Clean contacts, replace if necessary.
2. Poor fuel quality, vapor lock formation. Refuel with quality fuel.
3. Fuel supply too low. Check pump performance.
4. Defective fuel filter. Replace fuel filter.
5. Faulty fuel pump. Check fuel pump.
6. Faulty injectors. Check injectors.
7. Faulty throttle position sensor. Check throttle position sensor.
8. Weak fastening of the fuel hoses to the injection pump and the fuel filter of the diesel engine.
The engine runs intermittently during transients and idling
1. Leaky air intake system. Check intake system connections. Start the engine and lubricate the contact points and connections in the intake tract with gasoline. If the engine speed increases briefly, repair the leak.
2. Incorrect idle adjustment. Check idle air control, throttle position sensor, lambda control.
3. Full load sensor defective or incorrectly adjusted. Check the throttle sensor.
Hot engine won't start
1. Incorrect adjustment of the CO content. Check CO content and idle speed.
2. Too high pressure in the fuel system. Check fuel pressure, replace pressure regulator if necessary.
3. Clogged or bent return line between pressure regulator and fuel tank. Clean or replace piping.
4. Faulty engine temperature sensor. Check temperature sensor.
5. Leaky power system. Make a visual inspection of all connections in the area of the engine and electric fuel pump. Tighten all connections.
6. Leaky air intake system. Check all intake system connections.
Engine running after shutdown
1. Leaky injectors. Check injectors.
2. On a diesel engine, the fuel cut-off valve does not work.
Lubrication system
The control lamp does not burn after inclusion of ignition
1. Faulty oil pressure sensor. Turn the ignition on, disconnect the wire from the oil pressure sensor and short to ground. If the lamp lights up, replace the sensor.
2. The sensor is not energized, the contacts are corroded. Check electrical wires and contacts.
3. The control lamp is defective. Replace the control lamp.
4. Faulty control device. Replace control device.
The control lamp does not go out after starting the engine
The oil is overheated. If the control lamp goes out after the gas is applied, nothing needs to be done.
The control lamp does not go out after applying gas or lights up while driving
1. Oil pressure is too low. Check oil level, top up if necessary. Check oil pressure.
2. The wire to the oil pressure sensor has a short to ground. Disconnect the cable from the sensor and lay it aside (without grounding), turn on the ignition. If the lamp lights up, check the wire.
3. The oil pressure sensor is defective. Replace sensor.
Too low oil pressure at all speeds
1. Too little oil in the engine. Add oil.
2. Strainer clogged. Remove the oil pan, clean the strainer.
3. Worn oil pump. Remove the oil pump and check it, replace if necessary.
4. Bearing damage. Remove the engine.
Too low oil pressure at low speeds
Pressure reducing valve stuck open due to contamination. Remove and check the valve.
Oil pressure too high above 2000 rpm
Pressure reducing valve does not open due to contamination. Remove and check the valve.
Cooling system
Overheat
1. Not enough coolant in the system (Chapter Cooling, heating systems).
2. The water pump drive belt is worn or damaged or its tension is not adjusted.
3. The internal channels of the radiator are blocked or dirty (blocked) radiator grille (Chapter Cooling, heating systems).
4. Faulty thermostat (Chapter Cooling, heating systems).
5. Broken or cracked fan blades (Chapter Cooling, heating systems).
6. Faulty viscous fan clutch (models 320i, 323i, 328i with air conditioning). Check fan clutch: Increase engine speed when warm. As soon as the temperature of the liquid reaches 90 - 95°C, the fan speed will increase, which will be noticeable by ear.
7. Faulty coolant temperature gauge. Check sensor.
8. Faulty coolant pump. Remove and check the pump.
9. The radiator cap does not hold pressure. Perform a pressure test on the cap (contact a service station).
Hypothermia
1. Faulty thermostat (Chapter Cooling, heating systems).
2. The readings of the temperature meter are inaccurate.
External coolant leaks
1. Damaged or destroyed as a result of aging of the material, the hoses or loosened their fastening on the fittings. Replace hoses and/or tighten hose clamps (Chapter Cooling, heating systems).
2. Damaged water pump seals. In this case, the coolant will seep through the control hole in the pump housing (Chapter Cooling, heating systems).
3. There are leaks from the internal channels of the radiator or side reservoir (ov). Professional Radiator Repair Needed (a description of the removal procedure is given in Chapter Cooling, heating systems).
4. There are leaks from the engine drain plug (Chapter Engine) or squeeze plugs of water galleries (Chapter Cooling, heating systems).
Internal coolant leaks
Internal coolant leaks are usually identified by checking the condition of the engine oil. Inspect the feeler blade and inside surfaces of the cover (lids) cylinders for traces of water and oil foaming.
1. There are leaks from the cylinder head gasket. Perform a pressure test on the cooling system.
2. There are cracks in the cylinder walls or in the head casting. Disassemble the engine to check (Chapter Engine).
Loss of coolant occurs
1. Too much refrigerant in the system (Chapter Cooling, heating systems).
2. The coolant boils away as a result of engine overheating.
3. There are internal or external refrigerant leaks.
4. Faulty radiator cap. Check the cover with pressure.
Refrigerant circulation interrupted
1. The water pump is not functioning properly. The easiest way to verify the operation of the pump is to pinch the upper radiator hose while the engine is idling. If a push of liquid is felt inside the hose when the hose is released, the pump is functioning properly (Chapter Cooling, heating systems).
2. The patency of the cooling system is broken. Drain coolant, flush system and refill with fresh mix (Chapter Cooling, heating systems). If necessary, remove the radiator (Chapter Cooling, heating systems) and backflush it.
3. The water pump drive belt is worn or damaged or its tension adjustment is broken.
4. Stuck thermostat (Chapter Cooling, heating systems).
Heater
Heater fan not working
1. Fan motor fuse defective. Check fan fuse, replace if necessary.
2. Faulty fan switch. Check if voltage is being applied to the pre-resistors, remove and check the fan switch.
3. Faulty electric motor. Check if voltage is applied to the fan motor terminals with the ignition on and the fan switch closed. If voltage is applied, replace the motor.
The heater fan does not work on one of the stages
Faulty preresistor. Replace connection board.
The heater is not switched off by the regulator
1. Faulty switch. Check switch.
2. Control mixing flap cables are damaged or do not move well. Replace cables.
Heating power too low
1. Coolant level too low. Check coolant level, top up if necessary.
2. The heater control unit has a hard move, is defective. Check the heater control unit, replace the cable if necessary.
Noise in the heater fan area
1. Dirt, leaves got in. Remove the fan and clean it, clean the air channel.
2. Imbalance of the impeller, bearing failure. Remove the fan motor, check for ease of movement.
Clutch
Clutch won't disengage (the manual transmission control lever does not move freely into the reverse gear position and back when the clutch pedal is depressed to the floor)
Bent or damaged clutch disc (Chapter Clutch and drive shafts).
Clutch slips (engine speed increases without increasing vehicle speed)
1. The clutch disc is contaminated with oil or its friction linings are worn out. Remove the clutch (Chapter Clutch and drive shafts) and check the status of its components.
2. The clutch disc did not break in properly. It may take 30 to 40 normal starts of the car to finally break in a new disc.
3. Worn pressure plate/clutch basket (Chapter Clutch and drive shafts).
Vibration occurs when clutch is engaged
1. Oily clutch disc. Remove the clutch (Chapter Clutch and drive shafts) and check the status of its components. Repair any leaks found.
2. Driven disc hub splines worn (clutch disc). Remove the clutch (Chapter Clutch and drive shafts) and check the status of its components.
3. Bent pressure plate/clutch basket or flywheel. Remove the clutch (Chapter Clutch and drive shafts) and check the condition of its components and flywheel.
Jerks during clutch operation
1. Damage to engine and gearbox mounts. Check, replace if necessary.
2. Looseness of the gearbox mounting in the suspension. Tighten the mounting bolts.
3. Uneven fit of the pressure plate. Replace clutch basket.
4. The crankshaft is not centered with the gearbox. Check centering.
Squealing or rattling occurs when the clutch is fully engaged (pedal released)
Clutch release bearing stuck. Remove the clutch (Chapter Clutch and drive shafts) and check the condition of the bearing. Remove all burrs and nicks and lubricate the bearing before reinstalling.
Squealing or rattling occurs when the clutch is fully disengaged (pedal depressed)
1. Worn or damaged release bearing (Chapter Clutch and drive shafts).
2. Worn or damaged springs (or aperture blades) pressure plate in the clutch basket (Chapter Clutch and drive shafts).
Clutch pedal remains depressed to the floor after releasing it
Stuck clutch master or slave cylinder piston. Damage to the clutch hydraulic system or release bearing. Check the condition, if necessary, remove the clutch components.
Manual gearbox (RKPP)
When the gearbox is set to neutral, extraneous noises occur during engine operation
1. Worn input shaft bearing.
2. Drive shaft bearing damaged.
3. Worn intermediate shaft bearings.
4. Washers for adjusting the axial play of the intermediate shaft are worn or damaged.
Extraneous noises occur in any position of the manual transmission
1. Any of the above reasons and/or:
2. Insufficient amount of gear oil is filled in the manual transmission (his level dropped).
Extraneous noise occurs in any particular gear
1. Worn, damaged or chipped gear teeth of this gear.
2. The synchronizer of this transmission is worn out or damaged.
Going on "jumping off" Gearbox with top gear
Dirt has got between the gearbox boat and the engine or the gearbox has shifted in relation to the engine.
Complications occur when shifting gears
1. Not fully squeezed out (turned off) clutch.
2. The shift rod is damaged, its fastening is loose or the adjustment is broken. Make a thorough check of the condition of the components, if necessary, replace the defective ones.
Transmission oil leaks
1. Too much gear oil in the gearbox. Drain excess if necessary.
2. The differential seals need to be replaced.
Automatic transmission (AT)
Due to the complexity of the AT design, complete diagnostics of its malfunctions and repair of components are beyond the qualifications of the average amateur mechanic. In the event of any problems other than those listed below, the functioning of the AT, the car should be driven away for inspection and repair to a car service workshop or representative office of BMW.
General problems associated with the functioning of the switching mechanism
Among the failures associated with a violation of the adjustment of the shift rod are the following:
- a) The engine can be started in transmission positions other than "R" (parking) And "N" (neutral).
- b) The transmission position indicator reading is different from the actual gear selected.
- c) The vehicle is moving with the transmission in position "R".
Adjust the shift rod.
Transmission slips, shifts hard, makes strange noises or does not move the car when set to one of the forward or reverse gears
1. There are many possible causes for the problems listed in the title, but only one of them falls under the competence of an amateur mechanic - an incorrect transmission fluid level.
2. Before driving the car to a car service workshop, check the level and condition of the transmission fluid. Correct the level in accordance with the requirements of the Specifications or change the fluid along with the filter. If the situation does not improve, seek help from specialists.
Transmission fluid leaks
1. AT liquid has a dark red color. Traces of its leaks should not be confused with traces of impellent oil, which can be carried to the transmission crankcase by the oncoming air flow.
2. To identify and locate the source of the leak, first remove all traces of dirt and grease from the transmission boat. Use a suitable degreaser and/or steam clean. Then drive the car for a short trip at low speed (so that traces of the leak are not carried away by the oncoming flow far from its source). Stop, jack up the vehicle and locate the source of the leak by visual inspection. Most often these are:
- a) Transmission sump: Tighten mounting bolts and/or replace sump gasket.
- b) Fluid Fill Tube: Replace the rubber seal where the tube enters the transmission case.
- c) Transmission Fluid Lines: Tighten fittings or replace lines.
- d) Vent tube: Transmission overfilled and/or water ingested.
Bridges
Extraneous noise
1. Ordinary road noise. Not subject to correction.
2. Tire noise. Check the condition of the treads and tire inflation pressure.
3. Worn or damaged wheel bearings or loose torque.
Vibrations
Check the condition of the wheel bearings by alternately jacking the appropriate corner of the car and rotating the wheel manually. Listen for sounds coming from the bearing. Remove the bearings and check their condition.
Oil leaks
Damaged drive shaft seals (Chapter Clutch and drive shafts).
Brake system
Before concluding that there is a problem with the braking system, check that the tires are in good condition and inflated to the correct pressure, that the front wheel alignment is not out of alignment, and that the vehicle is not loaded unevenly.
Increased brake pedal travel
The brake circuit has failed. Check if brake fluid is leaking.
Brake pedal springs and falls
1. Air in the brake system. Remove air from the system.
2. Not enough liquid in the reservoir. Add new brake fluid, remove air from the system.
3. The formation of steam bubbles. It appears mainly when the brakes are heavily loaded. Change the brake fluid, remove air from the system.
Decreased braking effect, pedal fails
1. Leakage of the pipeline. Tighten tubing connections or replace tubes.
2. Damage to the cuffs in the main or working brake cylinders. Replace cuff. In the main brake cylinder, replace the internal elements, if necessary, replace the main cylinder
3. Damaged rubber gasket. Repair the caliper.
Poor braking despite high pedal pressure
1. Brake linings are oily. Replace brake pads.
2. Wrong or hardened pads installed. Replace pads. Install original BMW pads.
3. The brake booster is faulty. Check the brake booster.
4. Worn brake pads. Replace brake pads.
Vehicle pulls to one side when braking
1. The tire pressure is not correct. Check and correct tire pressure.
2. Uneven tire wear. Replace worn tires.
3. Brake pads are oily. Replace pads.
4. Different brake pads are installed on the same axle. Replace pads. Install original BMW pads.
5. Poor condition of the brake pads. Replace pads.
6. Contaminated caliper shafts. Clean the guides and seating surfaces of the pads in the caliper.
7. Corrosion of brake caliper cylinders. Replace caliper.
8. Uneven brake pad wear. Replace brake pads (on both wheels).
Brake tightens by itself
1. The compensation hole in the main brake cylinder is clogged. Clean the master cylinder and replace the internals.
2. The gap between the drive rod and the master cylinder piston is too small. Check clearance.
Brakes get hot while driving
1. The compensation hole in the main brake cylinder is clogged. Clean the master cylinder and replace the internals.
2. The gap between the drive rod and the master cylinder piston is too small. Check clearance.
3. The throttling hole in the special valve on the bottom is clogged. Clean the main brake cylinder, replace the internal elements and brake fluid.
The brakes are shaking
1. Wrong pads installed. Replace pads, install original BMW pads.
2. The brake disc is corroded in places. Carefully sand the brake disc.
3. The brake disc has lateral runout. Repair or replace the disk.
Brake pads do not move away from the brake disc, the wheel is difficult to turn by hand
Corrosion in brake caliper cylinders. Repair the caliper, possibly replace it.
Uneven pad wear
1. Wrong pads installed. Replace pads, install original BMW pads.
2. The caliper is dirty. Clean out the caliper shaft.
3. Heavy piston stroke. Eliminate.
4. The brake system is leaking. Check the tightness of the brake system.
Wedge-shaped brake pad wear
1. The brake disc does not rotate parallel to the caliper. Check the contact surfaces of the caliper.
2. Corrosion in calipers. Eliminate contamination.
3. The piston is not working properly. Check piston position.
Screeching brakes
1. Often the cause is atmospheric influence (air humidity). If a creak appears after a long stay in high humidity and then disappears, nothing needs to be done.
2. Wrong pads installed. Replace the pads, install genuine BMW pads, coat the base plates with anti-squeak paste.
3. The brake disc does not rotate parallel to the caliper. Check the contact surfaces of the brake caliper.
4. The caliper shaft is dirty. Clean the caliper shaft
5. The springs for fastening the pads are bent. Replace mounting springs.
6. Compression springs stretched. Replace compression springs.
Pulsation of the brake pedal
1. ABS in action. OK, no help needed.
2. Too much lateral runout or brake disc thickness tolerance. Check runout and thickness. Repair or replace the disc.
3. The brake disc does not rotate parallel to the caliper. Check the contact surface of the caliper.
The ABS warning light comes on while driving
1. Supply voltage too low (below 10 V). Check voltage. Check if the generator control lamp goes out after starting the engine. If everything is in order, check the alternator drive V-belt.
2. ABS damage. Check for good contact and corrosion at the ground connection on the return pump (in the hydraulic block).
Suspension and steering
Vehicle pulls to one side when moving
1. Tires are unevenly inflated.
2. There is a tire defect.
3. Excessively worn suspension or steering components (Chapter Suspension and steering).
4. Front wheel alignment required.
5. Stuck front brakes (Chapter Brake system).
There are jerks, jerks or vibrations
1. The wheels are out of balance or the discs are oval. Have the tire balanced at a tire shop.
2. Worn wheel bearings, loose torque or out of adjustment (Chapter Suspension and steering).
3. Worn or damaged shock absorbers or other suspension components (Chapter Suspension and steering).
There is excessive rocking of the vehicle or "burying" his nose when cornering or braking
1. Defective shock absorbers. Replace the whole set (Chapter Suspension and steering).
2. Broken or loose springs and/or other suspension components. Check the status of the components (Chapter Suspension and steering).
Steering wheel too tight
1. The fluid level in the reservoir of the power steering system has dropped excessively (Chapter Suspension and steering).
2. Tires not properly inflated.
3. Insufficiently lubricated steering gear joints (Chapter Suspension and steering).
4. The adjustment of the angles of installation of the front wheels is broken.
5. The hydraulic booster does not develop the required power.
There is excessive steering play
1. The tightening force of the front wheel bearings has weakened (Chapter Suspension and steering).
2. Excessively worn suspension or steering components (Chapter Suspension and steering).
The power steering system does not develop the proper force
1. The power steering pump drive belt is worn or damaged or its tension is not adjusted (Chapter Suspension and steering).
2. Hydraulic fluid level too low (Chapter Suspension and steering).
3. The patency of the hoses or lines of the hydraulic system is broken. Check and replace if necessary.
4. Air has entered the hydraulic system. Bleed the system (Chapter Suspension and steering).
Excessive tread wear (not in one area)
1. Tires not properly inflated.
2. The wheels are out of balance. Contact a tire shop
3. Damaged wheel rims. Check and replace if necessary.
4. Excessively worn suspension or steering components (Chapter Suspension and steering).
Excessive tread wear on outer edge
1. Tires not properly inflated.
2. Too sharp turns are made. Reduce your speed.
3. The adjustment of the angles of installation of the front wheels is broken (excessive convergence). Contact a workshop for professional adjustment.
4. Bent or twisted suspension arm (Chapter Suspension and steering).
Excessive tread wear on the inside edge
1. Tires not properly inflated.
2. The adjustment of the angles of installation of the front wheels is broken (divergence). Carry out the adjustment at a car service workshop.
3. Steering components damaged or loose (Chapter Suspension and steering).
There is localized tread wear
1. The wheels are out of balance.
2. Damaged or bent discs. Check and replace if necessary.
3. There is a tire defect.
Wiper blade defects
Slippage
1. Rubber bands are dirty. Clean the rubber bands with a stiff nylon brush and detergent solution or alcohol.
2. Frayed edges of the brushes, rubber bands worn or torn. Replace rubber bands.
3. Old rubber bands, cracked surfaces. Replace rubber bands.
In the cleaning field, the remaining water immediately collects in drops
The windshield is dirty with lacquer polish or oil. Clean the windshield with a clean cloth with grease, oil, silicone remover.
The brush cleans one-sidedly - one side is good, the other is not
1. The elastic is deformed to one side "no longer tip over". Install new rubber.
2. The wiper arm is twisted, the blade does not fit exactly on the glass. Carefully turn the lever until the vertical position is reached.
Uncleaned surfaces
1. The elastic has come loose from the frame. Carefully insert the elastic into the frame.
2. The brush does not adhere to the glass evenly, as the spring bars or plates are bent. Replace brush. This malfunction first of all appears at careless installation of a spare brush.
3. Lever pressure is too low. Lightly lubricate the wiper arm pivots and springs, or install a new arm.
Tire defects
Heavy tire wear on both sides of the running surface
Tire pressure too low.
Strong tire wear in the middle of the working surface, around the entire circumference
Too high tire pressure.
Uneven tread wear
Static and dynamic wheel imbalance. Perhaps too much lateral runout of the disc, too much play in the bearing joints.
Uneven wear in the middle of the tread
Static wheel imbalance. Possible consequence of a strong vertical beat.
Strong wear of individual places in the middle of the working surface
Traces of blocking at full braking.
Sawtooth tread wear. Often accompanied by a tear in the fabric base that is not visible from the outside
Vehicle overload. Check the inside of the tire for warp breaks.
Rubber tabs on the side edges of the tread
Incorrect wheel alignment. The tire is worn out. On the rear wheels, also check the condition of the shock absorber.
Burr formation on one side of the front wheel tread
Incorrect toe adjustment. The tire is worn out. Frequent movement on undulating surfaces. Fast cornering.
Cord breaks. At first visible only from the inside
Driving over sharp rocks, tire bumps, etc. at high speed.
One-sided worn work surface
1. Check camber adjustment.
2. ABS damage. Check the reliability of the contact of the connection with the body at the return pump (in the hydraulic block).