Test KH - Service Pin Adjustment
NOTE:
Perform this test only when Code 57 OR 59 is displayed during QUICK TEST procedure or directed here by a driveability symptom. This test is intended to diagnose only the following components or circuits:
- Harness circuits (OCTANE ADJUST, IDLE ADJUST)
- Service pin connector shell (jumper wire)
- 1) Check if Octane Adjust Jumper Wire is Installed If the service pin connector is installed in the vehicle harness connector, then Code 57 is not a fault code but an information code, indicating that the service pin jumper wire is installed or circuit No. 23 is shorted to ground. For additional information on the octane adjust circuit, go to step 3. Locate the 3-pin service connector. If jumper wire is installed, Code 57 indicates service pin in use. Do not remove, testing is complete. If jumper is not installed, go to next step.
- 2) Check For Short To Ground Turn key off. Disconnect ECA 60-pin connector. Inspect for corroded or damaged connector pins and repair as necessary. Install breakout box, leaving ECA disconnected. Set DVOM on 200-k/ohm scale. Measure resistance between test pin No. 23 and test pins No. 20, 40 and 60. If each resistance is greater than 10 k/ohms, replace ECA. Remove breakout box and rerun QUICK TEST PROCEDURES . If each resistance is not greater than 10 k/ohms, repair short to ground. Remove breakout box and rerun QUICK TEST.
- 3) Octane Adjust Pin
The purpose of the octane adjust pin is to provide optimum spark advance. If the vehicle spark knocks, install the service pin connector (jumper wire) to the vehicle harness connector. This will retard ignition timing 4 degrees. A Code 57 will be displayed to indicate service pin is in use. If vehicle continues to spark detonate, use gasoline with a higher octane rating.
NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 3 to step 10. No test procedures have been omitted.
- 10) Check If Idle Adjust Wire is Installed If the service pin connector is installed in the vehicle harness connector, Code 59 is not a fault code but an information code, indicating that the jumper wire is installed or circuit No. 28 is shorted to ground. For additional information on the idle adjust circuit, go to step 12. Locate the 3-pin connector. If jumper wire is installed in circuit 28 of the service pin connector, Code 59 indicates service pin in use. Do not remove, testing is complete. If jumper is not installed, go to next step.
- 11) Check For Short To Ground Turn key off. Disconnect ECA 60-pin connector. Inspect for corroded or damaged connector pins and repair as necessary. Install breakout box, leaving ECA disconnected. Set DVOM on 200-k/ohm scale. Measure resistance between test pin No. 28 and test pins No. 20, 40 and 60. If each resistance is greater than 10 k/ohms, replace ECA. Remove breakout box and rerun QUICK TEST PROCEDURES . If each resistance is not greater than 10 k/ohms, repair short to ground. Remove breakout box and rerun QUICK TEST.
- 12) Idle Adjust Pin The purpose of the idle adjust pin is to increase engine RPM due to additional engine loads. If the vehicle's curb idle appears to be low during parking maneuvers or vehicle stalls with A/C on, connect grounded jumper wire to IDLE ADJUST circuit No. 28 at the 3-pin service pin connector. This will retard ignition timing 4 degrees. A Code 59 will be displayed to indicate service pin is in use. If vehicle continues to exhibit driveability concerns, adjust idle speed.