Test D: Tachometer Inoperative Or Inaccurate
- If vehicle has been checked for DTCs, go to next step. If vehicle has not been checked for DTCs, check for DTCs. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
- Check for open, excessive resistance, electromagnetic interference or short (to ground or voltage) in White wire between instrument cluster harness connector terminal D8 and ignition control module harness connector C1 terminal "C". See Figure
and Fig 1
. If concern exists, go to next step. If concern does not exist, go to step 4
.
- Repair White wire between instrument cluster and ignition control module as necessary. Recheck system operation. If concern still exist, go to next step.
- Replace instrument cluster. See INSTRUMENT CLUSTER
under REMOVAL & INSTALLATION. Recheck system operation.
Courtesy of GENERAL MOTORS CORP.