LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Acura >> 2004 >> MDX Base >> Repair and Diagnosis >> Engine Performance >> System >> Idle Control System >> PSP Switch Signal Circuit Troubleshooting
April 5, 2026: LEMON Manuals is launched! Read the announcement.

PSP Switch Signal Circuit Troubleshooting

  1. Start the engine, and let it idle.
  2. Align the steering wheel straight ahead.
  3. Check the PSP SWITCH in the DATA LIST with the HDS.

    Does it indicate ON? 

    1. YES  - Go to step 4.
    2. NO  - Go to step  12.
  4. Turn the steering wheel to the full lock position.
  5. Check the PSPSW in the DATA LIST with the HDS.

    Does it change to OFF? 

    1. YES  - The PSP switch signal circuit is OK.
    2. NO  - Go to step 6.
  6. Turn the ignition switch OFF.
  7. Disconnect the PSP switch 2P connector.
  8. Start the engine.
  9. Check the PSPSW in the DATA LIST with the HDS.

    Does it change to OFF? 

    1. YES  - Replace the PSP switch.
    2. NO  - Go to step 10.
  10. Turn the ignition switch OFF.
  11. Jump the SCS line with the HDS.
  12. Disconnect PCM connector B (56P).
  13. Check for continuity between PSP switch 2P connector terminal No. 1 and body ground.
    Fig 1: Checking Continuity Between PSP Switch 2P Connector Terminal No.1 And Body Ground
    G03639911Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  - Repair short in the wire between the PSP switch connector and the PCM, then recheck.
    2. NO  - Update the PCM if it does not have the latest software, or substitute a known-good PCM (see PCM UPDATING AND SUBSTITUTION FOR TESTING ), then recheck. If the symptom/ indication goes away with a known-good PCM, replace the original PCM (see PCM REPLACEMENT ).
  14. Turn the ignition switch OFF.
  15. Disconnect the PSP switch 2P connector.
  16. Connect PSP switch 2P connector terminals No. 1 and No. 2 with a jumper wire, then start the engine.
    Fig 2: Connecting PSP Switch 2P Connector Terminals No. 1 And No. 2 With A Jumper Wire
    G03639912Courtesy of AMERICAN HONDA MOTOR CO., INC.
  17. Check the PSP switch in the DATA LIST with the HDS.

    Does it change to ON? 

    1. YES  - Replace the PSP switch.
    2. NO  - Go to step 18.
  18. Turn the ignition switch OFF.
  19. Remove the jumper wire from the PSP switch 2P connector.
  20. Jump the SCS line with the HDS.
  21. Disconnect PCM connector B (56P).
  22. Check for continuity between PCM connector terminal B55 and PSP switch 2P connector terminal No. 1.
    Fig 3: Checking Continuity Between PCM Connector Terminal B55 And PSP Switch 2P Connector Terminal No. 1
    G03639913Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  - Go to step 23.
    2. NO  - Repair open in the wire between the PSP switch connector and the PCM, then recheck.
  23. Check for continuity between PSP switch 2P connector terminal No. 2 and body ground.
    Fig 4: Checking Continuity Between PSP Switch 2P Connector Terminal No. 2 And Body Ground
    G03639914Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  - Update the PCM if it does not have the latest software, or substitute a known-good PCM (see PCM UPDATING AND SUBSTITUTION FOR TESTING ), then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM (see PCM REPLACEMENT ).
    2. NO  - Repair open in the wire between the PSP switch connector and body ground (G503), then recheck.
scientia non olet · About LEMON Manuals