Civic (D16Y5 Engine With M/T) & Prelude
- Turn ignition off. Disconnect A/C pressure switch and A/C diode (Prelude) connectors. See A/C SIGNAL COMPONENT LOCATIONS table. Turn ignition on. Using backprobe set, measure voltage between PCM 32-pin connector "A" terminal No. 9 (Brown/Black wire) and 31-pin connector "C" terminals No. 5 (Blue/Red wire on Civic, or Blue/Orange on Prelude). See PIN VOLTAGE CHARTS article. If 5 volts (Civic) or battery voltage (Prelude) exists, go to step 3. If specified voltage does not exist, go to next step.
- Turn ignition switch off. Disconnect PCM 31-pin connector "C". Check for continuity between ground and PCM 31-pin harness connector "C" terminal No. 5 (Blue/Red wire on Civic, or Blue/Orange on Prelude). If continuity exists, repair short in Blue/Red wire between PCM 31-pin connector "C" and A/C pressure switch. If continuity does not exist, substitute a known-good PCM and recheck. See SUBSTITUTING PCM in SELF-DIAGNOSTICS - INTRODUCTION article. If symptom or indication goes away, replace original PCM. If continuity still does not exist, inspect A/C system. See appropriate A/C-HEATER SYSTEMS article.
- Turn ignition off. Reconnect A/C pressure switch and A/C diode (Prelude) connectors. Turn ignition on. Using backprobe set, momentarily connect a fused jumper wire between PCM 32-pin connector "A" terminals No. 9 (Brown/Black wire) and No. 17 (Black/Red wire on Civic, or Pink/Blue wire on Prelude), several times. If A/C compressor clutch makes a clicking sound, go to step 5. If A/C compressor clutch does not make a clicking sound, go to next step.
- On Civic, using backprobe set, momentarily connect a fused jumper wire between ground and under-hood fuse/relay box 9-pin connector terminal No. 5 (Black/Red wire), several times. See Fig 2. On Prelude, using backprobe set, momentarily connect a fused jumper wire between ground and A/C clutch relay connector terminal No. 4 (Pink/Blue wire), several times. See Fig 3. See A/C SIGNAL COMPONENT LOCATIONS table. On all models, if A/C compressor clutch makes a clicking sound, repair open in Black/Red wire (Civic) or Pink/Blue wire (Prelude) between PCM 32-pin connector "A" terminal No. 17 and under-hood fuse/relay box 9-pin connector terminal No. 5 on Civic, or A/C clutch relay on Prelude. See WIRING DIAGRAMS article. If A/C compressor clutch does not make a clicking sound, inspect A/C system. See appropriate A/C-HEATER SYSTEMS article.
- Start engine. Turn A/C and blower motor switches on. If A/C operates, A/C signal is okay. If A/C does not operate, go to next step.
- Using backprobe set, measure voltage between PCM 32-pin connector "A" terminal No. 9 (Brown/Black wire) and 31-pin connector "C" terminal No. 5 (Blue/Red wire on Civic, or Blue/Orange on Prelude). If less than one volt does not exist, repair open in Blue/Red (Civic) wire or Blue/Orange (Prelude) wire between A/C pressure switch and PCM 31-pin connector "C". If less than one volt exists, substitute a known-good PCM and recheck. See SUBSTITUTING PCM in SELF-DIAGNOSTICS - INTRODUCTION article. If symptom or indication goes away, replace original PCM. If specified voltage still does not exist, inspect A/C system. See appropriate A/C-HEATER SYSTEMS article.
A/C SIGNAL COMPONENT LOCATIONS
| A/C Component | Location | |
|---|---|---|
| Accord | ||
| Clutch Relay | Under-Hood Fuse/Relay Box | |
| Pressure Switch | On Receiver/Dryer, At Right Front Corner Of Condenser | |
| Civic | ||
| Clutch Relay | Under-Hood Fuse/Relay Box | |
| Pressure Switch | On A/C Line, At Left Front Corner Of Engine Compartment, Next To Power Steering Fluid Reservoir | |
| CR-V | ||
| Clutch Relay | Under-Hood Fuse/Relay Box | |
| Pressure Switch | On Receiver/Dryer, At Left Front Corner Of Engine Compartment, Next To Power Steering Fluid Reservoir | |
| Odyssey | ||
| Clutch Relay | Under-Hood Fuse/Relay Box | |
| Pressure Switch | On A/C Line, At Right Side Of Engine Compartment, Under Fuse/Relay Box | |
| Prelude | ||
| Clutch Relay | Left Front Corner Of Engine Compartment, Next To ABS Modulator Unit | |
| Diode | Left Front Of Passenger's Footwell, Under Middle Of Instrument Panel | |
| Pressure Switch | Next To Receiver/Dryer, At Right Front Corner Of Condenser | |
| S2000 | ||
| Clutch Relay | Main Under-Hood Fuse/Relay Box, Next To Battery | |
| Pressure Switch | On Receiver/Dryer, At Center Front Of Condenser | |