Pinpoint Test D: The Tachometer Is Inoperative
WARNING: This page is about a different car, the 2006 Mercury Grand Marquis and 2006 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.
- D1 RETRIEVE THE RECORDED DIAGNOSTIC TROUBLE CODES (DTCs) FROM BOTH THE CONTINUOUS AND ON-DEMAND PCM SELF-TESTS
- Check for recorded PCM DTCs from the continuous and on-demand self-tests.
- Are any PCM DTCs recorded?
Yes : REFER to the INTRODUCTION - GASOLINE article to continue diagnosis of the DTCs.
No : GO to D2.
- D2 CARRY OUT THE INSTRUMENT CLUSTER ON-DEMAND SELF-TEST ACTIVE COMMAND USING THE DIAGNOSTIC TOOL
- Key in ON position.
- Enter the following diagnostic mode on the scan tool: Instrument Cluster Active Command.
- Select the instrument cluster on-demand self-test active command. Trigger the on-demand self-test on. Observe the tachometer gauge.
- Does the tachometer gauge sweep from 0 to 7,000 rpm, and return to 0?
Yes : GO to D4.
No : GO to D3.
- D3 CHECK FOR CORRECT INSTRUMENT CLUSTER OPERATION
- Disconnect the instrument cluster connector.
- Check for:
- corrosion
- pushed-out pins
- Connect the instrument cluster connector and make sure it seats 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.
- D4 CHECK FOR CORRECT 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.