Climate Control Communication Circuit Troubleshooting

WARNING: This page is about a different car, the 2006 Honda Odyssey and 2005 Honda Odyssey. However, it is still accessible from the selected car via links, so may be relevant.

Disconnect the climate control unit 30P connector.
Disconnect the climate control panel 5P connector.
Disconnect the rear climate control unit 22P connector.
Disconnect the rear control panel 5P connector.
Check for continuity between the No. 23 terminal of the climate control unit 30P connector and the No. 2 terminal of the climate control panel 5P connector.

Fig 1: Checking Continuity Between No. 23 Terminal Of Climate Control Unit 30P Connector And No. 2 Terminal Of Climate Control Panel 5P Connector
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Go to step 6.
2. NO - Repair an open in the wire between the climate control unit 30P connector and the climate control panel 5P connector.
Check for continuity between the No. 23 terminal of the climate control unit 30P connector and the No. 2 terminal of the rear control panel 5P connector.

Fig 2: Checking Continuity Between No. 23 Terminal Of Climate Control Unit 30P Connector And No. 2 Terminal Of Rear Control Panel 5P Connector
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Go to step 7.
2. NO - Repair an open in the wire between the climate control unit 30P connector and the rear control panel 5P connector.
Check for continuity between the No. 23 terminal of the climate control unit 30P connector and the No. 17 terminal of the rear climate control unit 22P connector.

Fig 3: Checking Continuity Between No. 23 Terminal Of Climate Control Unit 30P Connector And No. 17 Terminal Of Rear Climate Control Unit 22P Connector
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Go to step 8.
2. NO - Repair an open in the wire between the climate control unit 30P connector and the rear climate control unit 22P connector.
Check for continuity between the No. 23 terminal of the climate control unit 30P connector and body ground.

Fig 4: Checking Continuity Between No. 23 Terminal Of Climate Control Unit 30P Connector And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Repair a short to body ground in the wire between the climate control unit, climate control panel, rear climate control unit and the rear control panel.
2. NO - Substitute a known-good rear control panel, climate control panel, climate control unit, and rear climate control unit one at a time, rechecking the system after each substitution. Replace the unit that eliminates the symptom/indication.