Climate Control Power and Ground Circuit Troubleshooting

1. Check the No. 30 (7.5 A) fuse in the under-dash fuse/relay box.

Is the fuse OK?

YES | - | Go to Step 2 .
NO | - | Replace the fuse, and recheck.■

1. Disconnect climate control unit connector B (16P).

1. Turn the ignition switch ON (II).

1. Measure the voltage between the No. 4 terminal of climate control unit connector B (16P) and body ground.

Is there battery voltage?

YES | - | Go to Step 5 .
NO | - | Repair open in the wire between the No. 30 fuse in the driver′s under-dash fuse/relay box and the climate control unit.■

1. Turn the ignition switch OFF.

1. Check for continuity between the No. 6 terminal of climate control unit connector B (16P) and body ground.

Is there continuity?

YES | - | Go to Step 7 .
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 G503.■

1. Perform the A/C communication in the Self-Diagnostic Function to obtain the IS-BUS communication varification status.

Is the communication OK?

YES | - | Check for loose wires or poor connections at climate control unit connector B (16P). If the connections are good, substitute a known-good climate control unit and printed circuit board, and recheck. If the symptom/indication goes away, replace the original climate control unit and printed circuit board.■
NO | - | Check for loose wires or poor connections at climate control unit connector B (16P). 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 .■