HVAC Control Power and Ground Circuit Troubleshooting
- 1. Fuse check:
- 1. Check the following fuse.
Fuse No. B22 (7.5 A) Location 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, repair a short in the No. B22 (7.5 A) fuse circuit.
- 2. Open wire check (IG2 A/C line):
- 1. Disconnect the following connector.
HVAC control unit 32P connector - 2. Turn the vehicle to the ON mode.
- 3. Measure the voltage between test points 1 and 2.
Test condition Vehicle ON mode HVAC control unit 32P connector: disconnected Test point 1 HVAC control unit 32P connector No. 12 Test point 2 Body ground Is there battery voltage?
YES
The IG2 A/C wire is OK. Go to step 3.
NO
Repair an open in the wire between the No. B22 (7.5 A) fuse in the under-dash fuse/relay box and the HVAC control unit.
- 3. Open wire check (GND line):
- 1. Turn the vehicle to the OFF (LOCK) mode.
- 2. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode HVAC control unit 32P connector: disconnected Test point 1 HVAC control unit 32P connector No. 5 Test point 2 Body ground Is there continuity?
YES
The GND wire is OK. Replace the HVAC control unit .
NO
Check for an open in the wire between the HVAC control unit and body ground. If the wire is OK, check for poor ground at G502).