Air Conditioning Signal: 3.5RL
- Turn ignition off. Disconnect radiator fan control unit Black 12-pin connector located under front passenger's footrest on main wire harness. Turn ignition on. Backprobing, measure voltage between PCM 26-pin connector terminal No. 26 (Brown/Black wire) and PCM 12-pin connector terminal No. 2 (Pink wire). See Figure. If battery voltage exists, go to step 3). If battery voltage does not exist, go to next step.NOTE: When substituting PCM, immobilizer code must be rewritten to replacement PCM using Honda PGM tester or engine will not start.
- Turn ignition off. Disconnect PCM 12-pin connector. Check continuity between ground and PCM 12-pin harness connector terminal No. 2 (Pink wire). If continuity exists, repair short in Pink wire between PCM and radiator fan control unit. If continuity does not exist, substitute a known good PCM, then recheck. If symptom or indication goes away, replace original PCM. Ensure A/C is operating properly. See A/C-HEATER SYSTEM article in AIR CONDITIONING & HEAT section.
- Turn ignition off. Reconnect radiator fan control unit connector. Turn ignition on. Using a jumper wire, backprobing, momentarily connect PCM 26-pin connector terminals No. 8 (Red/White wire) and No. 26 (Brown/Black wire), several times. See Figure. If A/C compressor clutch clicks, go to step 5). If A/C clutch does not click, go to next step.
- Locate A/C clutch relay in underhood relay box "A" at left front of engine compartment, between battery and upper radiator hose. Using a jumper wire, backprobing, connect A/C clutch relay connector terminal No. 4 (Red/White wire) to ground, several times. If A/C clutch clicks, repair open in Red/White wire between PCM 26-pin connector and A/C clutch relay. If A/C clutch does not click, other A/C problems exist. See A/C-HEATER SYSTEM article in AIR CONDITIONING & HEAT section.
- Start engine. Turn blower and A/C switches on. If A/C operates,A/C signal is okay. If A/C does not operate, backprobing, measure voltage between PCM 26-pin connector terminal No. 26 (Brown/Black wire) and PCM 12-pin connector terminal No. 2 (Pink wire). See Figure.
- If voltage is not less than one volt, repair open in Pink wire between PCM 12-pin connector terminal No. 2 and radiator fan control unit. If voltage is less than one volt, substitute a known good PCM, then recheck. If symptom or indication goes away, replace original PCM. Ensure A/C is operating properly. See A/C-HEATER SYSTEM article in AIR CONDITIONING & HEAT section.