Engine Runs on 3 Cylinders
FAULT TRACING INFORMATIONConditions
^ DTCs absent.
^ Fault permanent.
Fault Sources
^ Break in ground lead to power stage.
^ Defective power stage.
^ Contact resistance in contacts.
TESTING PROCEDURE
Check Signal to Ignition Coil
^ Connect a voltmeter between DTC cylinder 1 at rear of engine and ground.
^ START engine.
Voltmeter should read 100 - 500 mV AC.
If value OK:
- Proceed to: Check Ground Lead to Rear Power Stage, section below.
If value differs:
- Proceed to: Check Ground Lead to Front Power Stage, section below.
Check Ground Lead to Rear Power Stage
^ Ignition OFF.
^ Disconnect rear power stage connector.
^ Connect an ohmmeter between power stage connector contact 4 and ground.
Ohmmeter should read approx. 0 ohms.
If value OK:
- Test with a new power stage.
If value differs:
- Check control point to rear power stage.
Check Control Point to Rear Power Stage
^ Ignition OFF.
^ Check rear power stage connector and control point for contact resistance and oxidation.
^ Connect an ohmmeter between power stage connector contact 4 and ground.
Ohmmeter should read approx. 0 ohms.
If value OK:
- Source of fault is bad contact in power stage connector or control point.
If value differs:
- Check lead between power stage and control point (31132) for break.
Check Ground Lead to Front Power Stage
^ Ignition OFF.
^ Disconnect front power stage connector.
^ Connect an ohmmeter between power stage connector contact 4 and ground.
Ohmmeter should read approx. 0 ohms.
If value OK:
- Test with a new power stage.
If value differs:
- Check control point to front power stage.
Check Control Point to Front Power Stage
^ Ignition OFF.
^ Check front power stage connector and control point contact resistance and oxidation.
^ Connect an ohmmeter between power stage connect contact 4 and ground.
Ohmmeter should read approx. 0 ohms.
If value OK:
- Source of fault is bad contact in power stage connector or control point.
If value differs:
- Check lead between power stage and control point (31/32) for break.