Coolant Temperature Gauge Troubleshooting
Before testing, check the No. 9 (10A) fuse in the under-hood fuse/relay box and the No. 10 (7.5A) fuse in the under-dash fuse/relay box.
|1.||Start the engine, and check the malfunction indicator lamp (MIL).|
Does the MIL come on and stay on?
YES - Troubleshoot the cause of the ECM/PCM DTC, and recheck.
NO - Go to 2.
|2.||Check for a multiplex control unit DTC.|
Is a DTC indicated?
YES - Troubleshooting the cause of the multiplex control unit DTC, and recheck.
NO - Go to 3.
|3.||Do the communication line check with the self-diagnosis procedure.|
Is the word ‘‘Error'' indicated on the odo/trip display?
YES - The gauge cannot receive the signal from the multiplex control unit and the ECM/ PCM. Check for an open in the GRY/RED wire (gauge connector terminal A1).
NO - Go to 4.
|4.||Do the gauge drive circuit check with the self-diagnosis procedure.|
Does the temperature gauge needle sweep from the minimum position to the maximum, then return to the minimum position?
YES - Go to 5.
NO - Replace the gauge assembly.n
|5.||Substitute a known-good ECM/PCM, and recheck.|
Did the symptom/indication go away?
YES - Replace the ECM/ PCM.
NO - Substitute a known-good gauge assembly. If the symptom/indication goes away, replace the gauge assembly.n