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Home >> GMC >> 1998 >> Envoy >> Repair and Diagnosis >> Electrical >> Gauges >> Instrument Panel >> Symptom Testing >> Tachometer Does Not Operate Properly

Tachometer Does Not Operate Properly

  1. Perform INSTRUMENT PANEL CLUSTER (IPC) SYSTEM CHECK  under SYSTEM TESTNG. Go to next step.
  2. Start engine. Using scan tool, check RPM. If RPM reading agrees with actual engine speed, go to next step. If RPM and engine speed are not the same, go to step 5).
  3. Compare scan tool reading to tachometer reading. If values are within 300 RPM, system is okay. If readings vary by more than 300 RPM, go to next step.
  4. Replace IPC. Perform INSTRUMENT PANEL CLUSTER (IPC) SYSTEM CHECK  under SYSTEM TESTING.
  5. Check for RPM input at IPC connector terminal A3 (White wire). See Figure . If RPM signal does not exist, go to next step. If RPM signal exists, see appropriate TESTS W/CODES article in ENGINE PERFORMANCE section:
  6. Check connectors and wiring between IPC and VCM/PCM. Repair as necessary. If problem was repaired, perform INSTRUMENT PANEL CLUSTER (IPC) SYSTEM CHECK  under SYSTEM TESTING. If no problem was found, see appropriate TESTS W/CODES article in ENGINE PERFORMANCE section:
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