Climate Control Power & Ground Circuit Troubleshooting

NOTE: Before performing symptom troubleshooting, check for powertrain DTC (see HOW TO USE THE HONDA DIAGNOSTIC SYSTEM (HDS) )

Check the No. 3 (7.5A) fuse in the driver's under-dash fuse/relay box.
Is the fuse OK?
1. YES - Go to step 2.
2. NO - Replace the fuse, and recheck.
Disconnect climate control unit connector B (30P).
Turn the ignition switch ON (II).
Measure the voltage between the No. 13 terminal of climate control unit connector B (30P) and body ground.

Fig 1: Measuring The Voltage Between The No. 13 Terminal Of Climate Control Unit Connector B (30P) & Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there battery voltage?
1. YES - Go to step 5.
2. NO - Repair open in the wire between the No. 3 fuse in the driver's under-dash fuse/relay box and the climate control unit.
Turn the ignition switch OFF.
Check for continuity between the No. 29 terminal of climate control unit connector B (30P) and body ground.

Fig 2: Checking For Continuity Between The No. 29 Terminal Of Climate Control Unit Connector B (30P) & Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Check for loose wires or poor connections at climate control unit connector B (30P). 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.
2. 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 G401.