Pinpoint Test 2

Flow Chart No. 2 - Symptom - Coolant temperature reads inaccurately.

Step 1
Verify power at fuse panel - load side.




1. Using voltmeter, verify system voltage at load side of warning indicator Fuse 11 (7.5 A).




2. Is system voltage present at load side of fuse?

Step 2
Verify power at fuse panel - feed side.
1. Using voltmeter, verify system voltage at feed side of warning indicator Fuse 11 (7.5 A).




2. Is system voltage present at feed side of fuse?

Step 3
Verify power at instrument cluster.




1. Partially remove cluster from instrument panel. Using voltmeter, verify system voltage at Pin 4 (R/Y) of 16-pin cluster connector or gauge terminal.
2. Inspect cluster connector for damage.




3. Is voltage present at cluster connector and gauge terminal?

Step 4
Verify ground circuitry at cluster.

CAUTION
^ Before checking the continuity of any circuit, make sure there is no voltage present in the circuit prior to switching the test equipment to the resistance function to avoid damage to equipment. Refer to test equipment user's manual for additional information.




1. Using ohmmeter, check continuity of 12-pin cluster connector and gauge ground B/W wire.




2. Is the resistance less than 1 ohm?

Step 5
Test sender circuit at cold.
1. Insert SST 4908 39285 or equivalent. Disconnect connector at sender and connect tester to R/W wire at cluster side of connector. Set to 74 ohms.




2. Does gauge read C?

Step 6
Test sender circuit at hot.
1. Set gauge system tester to 9.7 ohms.




2. Does gauge read H?

Step 7
Check sending unit circuit wiring.

CAUTION
^ Before checking the continuity of any circuit, make sure there is no voltage present in the circuit prior to switching the lest equipment to the resistance function to avoid damage to equipment. Refer to test equipment users manual for additional information.

1. Using ohmmeter, check sending unit circuit wiring and instrument cluster printed circuit for shorts or opens by physically flexing the wiring and observing continuity. The continuity reading should not fluctuate.




2. Are wiring and flex circuit OK?