Ignition System: Service Precautions

Safety Precautions

Observe the following if test and measuring instruments are required during a test drive:


Distraction and improperly secured test equipment can lead to accidents.

Risk of passenger airbag deploying in an accident.

• Operating testing and measuring equipment while driving creates a distraction.

• There is an increased risk of injury due to unsecured testing and measuring equipment.

• Always secure testers on the rear seat with a strap and have a second person on the rear seat to operate them.

To reduce the risk of personal injury and/or damage to the fuel injection and ignition system, always observe the following:

• Do not touch or remove ignition wires when engine is running or turning at starter speed.

• Always switch ignition off before disconnecting or reconnecting wires for the ignition system, including high voltage wiring and test leads.

• If engine is to be cranked at starting RPM without starting (for example for compression testing), disconnect connectors from ignition coils and from fuel injectors. After performing work, check and erase DTC memory.

• Cleaning the engine should only be performed with ignition switched off.

• The battery must only be disconnected and connected with the ignition switched off, since the engine control module (ECM) can otherwise be damaged.