Driver Complaint Sheet

Engine performance problem (odor, surge, fuel economy). Emission problem.

If "CHECK ENGINE" light is not on, normal checks that would be performed on cars without CCC should be done first.

If generator or coolant light is on with the "CHECK ENGINE" light, diagnose those systems first.

Inspect for poor connections at coolant sensor, M/C solenoid, etc. Check for poor or loose vacuum hoses and connections. Repair as needed.

INTERMITTENT "CHECK ENGINE" LIGHT, BUT NO TROUBLE CODE STORED:

1. Check for intermittent connection in circuit from:
   • Ignition coil to ground and arcing at spark plugs or wires.
   • Battery to ECM terminals "C" and "R".
   • ECM terminals "A" and "U" to engine ground.
2. Loss of long-term memory:

   Grounding dwell lead for 10 seconds with "test" lead ungrounded should give Code 23. Code should be retained after engine is stopped and ignition turned to "RUN" position. If it is not, ECM is defective.

3. EST wires should be kept away from spark plug wires, distributor housing, coil and generator. Wires from ECM Terminal 13 to distributor and the shield around EST wires should be a good ground.
4. Open diode across A/C compressor clutch.

   DETONATION (SPARK KNOCK)

   Check:

   • Vacuum Sensor output.
   • EGR operation.
   • TPS enrichment operation.
   • HEI operation.

   POOR PERFORMANCE OR FUEL ECONOMY

   See EST diagnosis.

   POOR FULL THROTTLE PERFORMANCE

   See Chart 4.

   ALL OTHER COMPLAINTS

   Make system performance check on warm engine (upper radiator hose hot).

   Always perform system performance check after any repairs to the system have been made.