Diesel Data: Automotive Repair

Climate Control Unit Power, Ground, And Communication Circuit Troubleshooting




Climate Control Unit Power, Ground, and Communication Circuit Troubleshooting

1. Check the No. 36 (10 A) fuse in the under-dash fuse/ relay box.

Is the fuse OK?

YES -

Go to step 2.

NO -

Replace the fuse, and recheck. If the fuse blows again, check for a short in the No. 36 (10 A) fuse circuit.�

2. Turn the ignition switch to ON (II).

3. Measure the voltage between climate control unit connector A (36P) terminal No. 19 and body ground.





Is there battery voltage?

YES -

Go to step 4.

NO -

Repair an open in the wire between the No. 36 (10 A) fuse in the under-dash fuse/relay box and the climate control unit.�

4. Measure the voltage between climate control unit connector A (36P) terminal No. 4 and body ground.





Is there less than 0.5 V?

YES -

Go to step 5.

NO -

Check for an open in the wire between the climate control unit and body ground. If the wire is OK, check for poor ground at G403.�

5. Turn the ignition switch to LOCK (0).

6. Disconnect climate control unit connector A (36P).

7. Check for continuity between the following terminals of the gauge control module 32P connector and climate control unit connector A (36P).









Is there continuity?

YES -

Check for loose wires or poor connections at climate control unit connector A (36P). If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit Climate Control Unit Removal/Installation.�

NO -

Repair an open in the wire between the climate control unit and the gauge control module.�