Motronic Injection System, Servicing

Motronic Injection System, Servicing

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

CAUTION: Fuel system is under pressure! Before opening system, place rags around the connection area. Then release pressure by carefully loosening connection.

- Only disconnect and reconnect wires for injection and ignition system, including test leads, when ignition is turned off.
- 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 therefore be checked and erased if necessary. Readiness code must be generated after DTC memory is erased.
- Always switch ignition off before cleaning engine.

CAUTION:
- For vehicles with Telematics, activate service mode of Telematics Control Module before disconnecting the battery.
- 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), obtain if necessary.







- Remove cover above the battery (arrows).

NOTE: For vehicles without separate battery cover: Remove plenum chamber cover.







- Disconnect battery Ground (GND) wire (arrow) with the ignition switched off.

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 Telematics Control Module.
- Generate readiness code.

If test and measuring equipment is required during road test, note the following:

CAUTION:
- Test and measuring equipment must always be secured to the rear seat and operated from there by a second person.
- If test and measuring equipment is operated from the passenger seat, the person seated there could be injured in the event of an accident involving deployment of the passenger-side airbag.