Attention! When removing and applying voltage, the following conditions must be observed:
- when disconnecting the battery, the data of the ECU-KSUD fault memory is lost, therefore, before disconnecting it, you should read the information from the fault memory, check the recorded fault messages and, after eliminating the faults, erase them;
- the plug connections (PC) should be connected (inserted) and disconnected only when the ignition is off and the control panel is removed.
- when removing and installing parts, relays, fuses, etc., fault codes may be recorded in the fault memory of the ECU KSUD with self-diagnosis, therefore, after completing work related to electrical equipment, always request the fault memory;
- check the recorded error messages and erase them after troubleshooting.
When replacing the ECU, you need to pay attention to the following:
- in each case, it is necessary to read the software and hardware level of the corresponding ECU-KSUD and vehicle units using the "DIS-tester", according to the "DIS" system manual in the "Coding" and "Programming" subsections;
- each unit's memory contains certain values that represent the base values. Depending on the engine's condition, the ECU receives different input signal values. The adaptive control system compares the input signal values with the base values (software) values stored in memory and generates commands to executive bodies;
- if the ECU is de-energized for a long time (more than one hour), then the adaptive control system loses the values stored in memory;
- when connecting a new ECU or an ECU with erased information, the adaptive control system must itself read the input signal values of the corresponding engine and save them as new base values;
- this operation after starting the engine can cause uneven idling and coasting failures, depending on the engine characteristics this period can be different;
- before installing a new or replacing an old ECU, you should, if possible, warm up the engine to operating temperature;
- after installing the ECU, let the car engine run at different crankshaft speeds.
[The original is located on the internet portal: www.bmwman.ru]