Safety precautions when working with the ignition system (BMW 5 Series E34)

Electronic ignition systems contain high voltages of up to 30,000 volts. Under adverse conditions, such as high humidity in the engine compartment, voltage spikes can break through the insulation. Touching ignition system components can cause an electric shock.

• To prevent injury to workers and/or damage to the ignition system, the following rules must be observed:
• When the engine is running or when starting it, do not touch or disconnect the spark plug wires with your hands.
• Disconnect the ignition system wires only when the ignition is off. When the ignition is on, high voltage can be generated by shaking the ignition distributor,
• Connecting and disconnecting control devices (rPM meter, stroboscope), and also ignition system wires should be done only with the ignition off.
• It is prohibited to connect a radio interference capacitor and a test lamp to terminal 1 (-) of the ignition coil.
• Do not connect measuring instruments or a stroboscope with a supply voltage of 12 volts to terminal 15 while the engine is running.
• Do not short-circuit terminal 1 and terminal 15 to ground. Do not connect terminal 1 to B+. Therefore, terminal 1 cannot be used to block the engine start when installing the security system yourself.
• Before turning the engine over with the starter(for example, compression testing) switch off the ignition and disconnect the wire from terminal 15 on the ignition coil. On vehicles with DME, remove the main fuel injection system relay (relay 2). Never start the engine with the distributor cap removed or with the ignition coil wires disconnected (terminal 4).
• It is not permitted to replace the ignition coil with a coil of a different type. Never install ignition coils designed for contact ignition systems.
• When heated to temperatures above +80°C (for example, when painting a car) it is prohibited to start the engine immediately after the warm-up phase.
• When carrying out electric welding work, disconnect the battery from the on-board network.
• Wash your car only with the ignition off.
• Persons with pacemakers are prohibited from working on the electronic ignition system.