Ignition Test

Symptom Of Fault.
Engine will not start.





Diagnostic Procedure.
1. Check the ignition discharge module's ground connection
- Connect a test lamp to battery positive (B+) and pin 6 of the ignition discharge module's connector.

Is the test lamp on?
YES:
^ Continue with point 2.
NO:
^ Check and rectify the wiring, including grounding point G7P. Then continue with point 4.





2. Check the ignition discharge module's 12 V supply
- Connect the test lamp to pin 10 of the ignition discharge module's connector and B -.
- Activate one of the ignition coils by means of the ISAT scan tool. The purpose of this is to cause the main relay to operate.

WARNING: The electronic ignition system generates up to 40,000 Volts. Such voltage can prove fatal to people with weak hearts or those who are fitted with a pacemaker. All due caution should therefore be observed when carrying out any work involving the ignition system.

IMPORTANT: The ignition discharge module must be positioned with the ignition coils facing down during the test so that the transformer oil will provide good insulation in the high-voltage part of the ignition coils.

Does the test lamp light up?
YES:
^ Continue with point 3.
NO:
^ continue as described in "Fault diagnosis, main relay".





3. Check the operation of the ignition discharge module
- Remove the ignition discharge module from the camshaft cover
- Fit test spark plugs (part No. 86 11 386) in the ignition discharge module.
- Ground the spark plugs using test cable 86 10 867.
- Activate each separate ignition coil, using the ISAT scan tool. Sparks should be produced on each spark plug that is activated.

Are sparks obtained?
YES:
^ Change the spark plugs and continue with point 4.
NO:
^ Change the ignition discharge module and proceed to point 4.

4. Final check:
- Try to start the engine. Did the engine start?
YES:
^ The remedial measure taken was correct.
NO:
^ The fault is not in the ignition system.