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Home >> Cadillac >> 1998 >> Seville SLS >> Repair and Diagnosis >> Body & Frame >> Body, Cab Control Systems >> Body Control Module >> Diagnosis & Testing >> DTC B1324: A/C Refrigerant OVERPRESSURE >> Diagnostic Procedures

Diagnostic Procedures

  1. Perform BCM diagnostic system check. See BCM DIAGNOSTIC SYSTEM CHECK  . After performing system check, go to next step.
  2. Turn ignition on. Using scan tool, observe A/C high side pressure. If A/C pressure status is low, go to step 5). If A/C pressure status is not low, go to next step.
  3. If A/C pressure status is high, go to next step. If A/C pressure status is not high, see DIAGNOSTIC AIDS.
  4. Disconnect A/C pressure sensor. Observe A/C high side pressure on scan tool. If scan tool reading is zero volts, go to step 12). If scan tool reading is not zero volts, go to step 11).
  5. Disconnect A/C pressure sensor. Connect a fused jumper wire between A/C pressure sensor harness connector terminals "B" (Gray wire) and "C" (Red/Black wire). See WIRING DIAGRAMS  . Observe A/C high side pressure on scan tool. If scan tool reading is 5 volts, go to step 16). If scan tool reading is not 5 volts, go to next step.
  6. Check voltage between A/C pressure sensor harness connector terminals "A" (Black wire) and "B" (Gray wire). If voltage reading is 5 volts, go to step 9). If voltage reading is not 5 volts, go to next step.
  7. Check for poor connection at PCM harness connector C1 terminal No. 67 (Gray wire). If connection is faulty, go to step 17). If connection is okay, go to next step.
  8. Check for open in Gray wire. If circuit is open, go to step 18). If circuit is okay, go to step 13).
  9. Check for open in PCM harness connector C1 terminal No. 56 (Red/Black wire). If circuit is open, go to step 17). If circuit is okay, go to next step.
  10. Check for open or short in Red/Black wire between PCM and A/C pressure sensor. If circuit is faulty, go to step 18). If circuit is okay, go to step 20).
  11. Check for short to voltage in Red/Black wire between PCM and A/C pressure sensor. If circuit is shorted, go to step 18). If circuit is okay, go to step 20).
  12. Check for short to voltage in Gray wire between PCM and A/C pressure sensor. If circuit is shorted, go to step 18). If circuit is okay, go to next step.
  13. Check for poor connection at PCM harness connector C1 terminal No. 50 (Black wire). If connection is faulty, go to step 18). If connection is okay, go to next step.
  14. Check for poor connection at A/C pressure sensor harness connector terminal "A" (Black wire). If connection is okay, go to next step. If connection is faulty, go to step 17).
  15. Check for open in Black wire between PCM and A/C pressure sensor. If circuit is open, go to step 18). If circuit is okay, go to step 19).
  16. Check for poor connection at A/C pressure sensor terminals "B" and "C". If connection is faulty, go to next step. If connection is okay, go to step 19).
  17. Replace faulty harness connector. After repairs, go to step 21).
  18. Repair open or short in circuit. After repairs, go to step 21).
  19. Replace A/C pressure sensor. After replacing A/C pressure sensor, go to step 21).
  20. Replace PCM. After replacing PCM, go to next step.
  21. Clear DTCs using scan tool. Using scan tool, observe A/C high side pressure. If A/C pressure status is normal, system is okay.
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