Ignition System: Service Precautions

Safety Precautions

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 disconnect ignition wires when engine is running or turning at starting RPM.
- Always switch ignition off before disconnecting or reconnecting wires for the injection and ignition system, including high voltage wiring and test leads.
- If engine is to be cranked at starting RPM without starting (e.g. for compression testing), disconnect connector from ignition coils and from fuel injectors.
- It is possible that the control module will recognize a malfunction and store a DTC during some tests. After completing all tests and repairs, DTC memory should be checked and erased if necessary. Readiness code must be generated after DTC memory is erased.
- Always switch ignition off before cleaning engine.

CAUTION:
- On vehicles equipped with Audi Telematics by OnStar (R), switch-off the emergency (back-up) battery for the Telematic/Telephone Control Module prior to disconnecting vehicle battery. Use must use the VAS 5051 or VAS 5052.
- The battery must only be disconnected and connected with the ignition switched off, since the Engine Control Module (ECM) can otherwise be damaged.

- Note radio code (for vehicles equipped with coded anti-theft radio / radio navigation system), determine if necessary.
- Switch ignition off and remove ignition key.







- Remove cover above the battery (arrows).







- Disconnect Ground (GND) wire -arrow- at battery.

NOTE:
- Be sure to activate vehicle features (radio/radio-navigation system, clock, electric window regulators) according to owner's manual when the battery is re-connected.
- Deactivate service mode of Telematic Control Module.

CAUTION:
- On vehicles equipped with Audi Telematics by OnStar (R), switch-off the emergency (back-up) battery for the Telematic/Telephone Control Module prior to disconnecting vehicle battery. Use must use the VAS 5051 or VAS 5052.
- The battery must only be disconnected and connected with the ignition switched off, since the Engine Control Module (ECM) can otherwise be damaged.

- Generate readiness code.