Pinpoint Test 8

Flow Chart No. 8 - Symptom - Tachometer not reflecting engine speed.

Step 1
Check supply to gauge.




1. Turn ignition switch to OFF position.
2. Partially remove instrument cluster panel to gain access to the cluster connectors.
3. Turn ignition switch to the ON position.
4. Using voltmeter, check voltage at R/Y wire at 16-pin cluster connector.




5. Is battery voltage present?

Step 2
Check gauge ground.




1. Using an ohmmeter connected to a known good ground, connect second lead to Pin 1 (B/Y).
2. Measure resistances.




3. Are resistances 5 ohms or less?

Step 3
Check tachometer input circuit.
1. Turn ignition switch to OFF position.
2. Disconnect cluster 16-pin connector.
3. Disconnect ignition coil connector.
4. Using an ohmmeter, measure resistance of TN wire from PCM connector to cluster 16-pin connector.




5. Is resistance 1.8 ohms or less?

Step 4
1. Check printed circuit for continuity from gauge connector and Pin 2 of 16-pin connector.




2. Is there continuity?