A/C Pressure Switch Circuit: S2000
- Turn ignition off. Disconnect A/C pressure switch 2-pin connector. Turn ignition on. Measure voltage between body ground and A/C pressure switch 2-pin connector terminal No. 2 (Blue/Red wire). If voltage reading is about 5 volts, go to next step. If voltage reading is not about 5 volts, go to step 4.
- Turn ignition switch off. Check continuity between terminals of A/C pressure switch. If continuity exists, go to next step. If continuity does not exist, go to step 5.
- Reconnect A/C pressure switch 2-pin connector. Disconnect heater control panel 30-pin connector. Turn ignition on. Measure voltage between ground and heater control panel 30-pin connector terminal No. 12 (Blue/White wire). See Fig 1. If voltage reading is not about 5 volts, repair open in Blue/White wire between heater control panel and A/C pressure switch connectors. If voltage reading is about 5 volts, check for loose wires and/or poor connections at heater control panel and A/C pressure switch connectors. See WIRING DIAGRAMS article. Repair any problems found. If wiring and connectors are okay, substitute a known-good heater control panel and retest. If system operates properly, replace heater control panel. See appropriate AUTOMATIC or MANUAL A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING.
- Ensure A/C switch is off. Backprobing, measure voltage between ground and PCM connector "A" (32-pin connector) terminal No. 27 (Blue/Red wire). See Figure. If voltage reading is about 5 volts, repair open in Blue/Red wire between PCM and A/C pressure switch connectors. If voltage reading is not about 5 volts, check for loose wires and/or poor connections at PCM connector. See WIRING DIAGRAMS article. Repair any problems found. If wiring and connectors are okay, substitute a known-good PCM and retest. See SUBSTITUTING POWERTRAIN CONTROL MODULE under SELF-DIAGNOSTIC SYSTEM in SELF-DIAGNOSTICS - S2000 article. If symptom or indication goes away, replace original PCM.
- Check A/C system pressures. If system pressures are within specifications, replace A/C pressure switch. If system pressures are not within specifications, repair A/C system pressure problem. See GENERAL SERVICING PROCEDURES article in GENERAL SERVICING in AIR CONDITIONING & HEATING.
Courtesy of AMERICAN HONDA MOTOR CO., INC.