Pinpoint Test H: The Tachometer Is Inoperative

H1 CARRY OUT THE INSTRUMENT CLUSTER TACHOMETER ACTIVE COMMAND USING THE DIAGNOSTIC TOOL
- Key in ON position.
- Enter the following diagnostic mode on the diagnostic tool: Instrument Cluster Active Command.
- Select the instrument cluster tachometer active command. Trigger the tachometer and scroll in increments of 10%. Monitor the tachometer gauge. The tachometer should increase in increments of approximately 700 rpm for each 10% change.
- Does the tachometer gauge reading increase within the specifications?
- Yes : GO to H3.
- No : GO to H2.
H2 CHECK FOR CORRECT INSTRUMENT CLUSTER OPERATION
- Disconnect all the instrument cluster connectors.
- Check for:
  - corrosion
  - pushed-out pins
- Connect all the instrument cluster connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
- Yes : INSTALL a new instrument cluster. REFER to INSTRUMENT CLUSTER . TEST the system for normal operation.
- No : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
H3 CHECK FOR CORRECT POWERTRAIN CONTROL MODULE (PCM) OPERATION

Disconnect all the PCM connectors.
Check for:
- corrosion
- pushed-out pins
Connect all the PCM connectors and make sure they seat correctly.
Operate the system and verify the concern is still present.
Is the concern still present?

Yes : INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS . TEST the system for normal operation.
No : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.