2001 Acura 3.5RLFACTORY OEM SERVICE PROCEDURE

Air Conditioning Signal: Integra

  1. Turn ignition off. Disconnect A/C pressure switch and A/C diode connectors. A/C pressure switch Gray, 2-pin connector is located at left front of engine compartment, between radiator and compressor. A/C diode White, 3-pin connector is located under right side of dash, behind kick panel. Turn ignition on. Measure voltage by backprobing between PCM 32-pin harness connector terminal No. 27 (Blue/Red wire) and 25-pin harness connector terminal No. 20 (Brown/Black wire). See Figure . If battery voltage is not present, go to next step. If battery voltage is present, go to step  3 .
  2. Turn ignition off. Disconnect PCM 32-pin harness connector. Check continuity between ground and PCM 32-pin harness connector terminal No. 27 (Blue/Red wire). If continuity is present, repair short in Blue/Red wire between PCM 32-pin harness connector terminal No. 27 and A/C pressure switch 2-pin harness connector or A/C diode 3-pin harness connector terminal No. 2. If continuity is not present, Cut temporary key from a non-immobilizer key blank and tape donor vehicle key to it backwards in order to deactivate immobilizer system during testing. Substitute known-good PCM, then recheck. If symptom or indication goes away, replace original PCM. Ensure A/C is operating properly. See MANUAL A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING.
  3. Turn ignition off. Reconnect A/C pressure switch and A/C diode connectors. Turn ignition on. Using fused jumper wire, momentarily connect PCM 32-pin harness connector terminal No. 17 (Black/Red wire) and PCM 25-pin harness connector terminal No. 20 (Brown/Black wire) several times. See Figure . If A/C clutch does not click, go to next step. If A/C clutch clicks, go to step  5 .
  4. Locate and unbolt underhood fuse/relay block. Locate 9-pin harness connector plugged into bottom of fuse/relay block. Using a fused jumper wire, momentarily connect terminal No. 5 (Black/Red wire) to ground several times. If A/C clutch clicks, repair open in Black/Red wire between PCM 32-pin harness connector terminal No. 17 and underhood fuse/relay block 9-pin harness connector terminal No. 5. If A/C clutch does not click, problem is with A/C system. See MANUAL A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING.
  5. Start engine. Turn blower motor switch on. Turn A/C switch on. If A/C operates, A/C signal is okay at this time. If A/C does not operate, measure voltage by backprobing between PCM 32-pin harness connector terminal No. 27 (Blue/Red wire) and PCM 25-pin harness connector terminal No. 20 (Brown/Black wire). See Figure . If voltage is one volt or more, repair open in Blue/Red wire between PCM 32-pin harness connector terminal No. 27 and A/C switch 8-pin harness connector terminal No. 2. If voltage is less than one volt, Cut temporary key from a non-immobilizer key blank and tape donor vehicle key to it backwards in order to deactivate immobilizer system during testing. Substitute known-good PCM, then recheck. If symptom or indication goes away, replace original PCM. Ensure A/C is operating properly. See MANUAL A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING.
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Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
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  • • The engine overheats, stalls repeatedly, or misfires under load.
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