Ignition System: Description and Operation

General Notes On Ignition System

NOTE:
- Only the components which specifically relate to the ignition system are dealt with here. For the other components of the injection and ignition system Repair Group 24.
- The Engine Control Module (ECM) is equipped with On Board Diagnostic (OBD).
- Components marked with * are checked via On Board Diagnostic (OBD). Refer to "Displaying and Reading Trouble Codes/With Manufacturer Scan Tool/DTC Memory Checking and Erasing", Testing and Inspection
- Components marked with **can be checked via Output Diagnostic Test Mode (DTM).
- For trouble-free operation of the electrical components, a voltage of at least 11.5 V is necessary.
- Disconnecting and connecting the battery must only be done with the ignition switched off, otherwise the Engine Control Module (ECM) could be damaged.
- Check DTC memory before carrying out repairs and for troubleshooting. Refer to "Displaying and Reading Trouble Codes/With Manufacturer Scan Tool/DTC Memory Checking and Erasing", Testing and Inspection
- During some checks it is possible that the control module will detect and store a Diagnostic Trouble Code (DTC). Therefore after completing all checks and repairs the DTC memory must be checked and if necessary erased, and then generate the readiness code. Refer to "Displaying and Reading Trouble Codes/With Manufacturer Scan Tool/DTC Memory Checking and Erasing", Testing and Inspection. Refer to "Monitors, Trips and/or Drive Cycle (Readiness Codes)/Generating Readiness Code", Testing and Inspection
- If the engine starts, runs for a short period and then stops, after troubleshooting, repairs or component tests, then the malfunction may lie with the Immobilizer which is blocking the Engine Control Module (ECM). In such cases the DTC memory must be checked and, if necessary, the control module adapted.