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Radiator and A/C Condenser Fan Low Speed Circuit Troubleshooting

NOTE:
  1. Check the No. 7 (30 A) fuse in the under-hood fuse/relay box, and the No. 36 (10 A) fuse in the under-dash fuse/relay box.

    Are the fuses OK? 

    YES  -Go to step 2.

    NO  -Replace the fuse(s), and recheck. If the fuse(s) blow again, check for a short in the No. 7 (30 A) and the No. 36 (10 A) fuse(s) circuit.

  2. Remove the radiator fan relay from the under-hood fuse/relay box, and test it (see POWER RELAY TEST ).

    Is the relay OK? 

    YES  -Go to step 3.

    NO  -Replace the radiator fan relay.

  3. Connect the HDS to the DLC.
  4. Turn the ignition switch to ON (II).
  5. Turn on the A/C.
  6. Check the FAN LOW CTRL in the PGM-FI Data List with the HDS.

    Is the FAN LOW CTRL on? 

    YES  -Go to step 7.

    NO  -Substitute a known-good PCM (see SUBSTITUTING THE PCM ), and retest. If the symptom/indication goes away with a known-good PCM, replace the original PCM (see PCM REPLACEMENT ).

  7. Turn the ignition switch to LOCK (0).
  8. Measure the voltage between radiator fan relay 4P socket terminal No. 1 and body ground.
    Fig 1: Measuring Voltage Between Radiator Fan Relay 4P Socket Terminal No. 1 And Body Ground
    G08090256Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Go to step 9.

    NO  -Replace the under-hood fuse/relay box (see REMOVAL AND INSTALLATION ).

  9. Connect radiator fan relay 4P socket terminals No. 1 and No. 2 with a jumper wire.
    Fig 2: Identifying Connection Between Radiator Fan Relay 4P Socket Terminals No. 1 And 2 Using Jumper Wire
    G08090257Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Do the A/C condenser and radiator fans run on low? 

    YES  -Go to step 10.

    NO  -Go to step  19.

  10. Disconnect the jumper wire.
  11. Turn the ignition switch to ON (II).
  12. Measure the voltage between radiator fan relay 4P socket terminal No. 3 and body ground.
    Fig 3: Measuring Voltage Between Radiator Fan Relay 4P Socket Terminal No. 3 And Body Ground
    G08090258Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  --Go to step 13.

    NO  -Go to step  37.

  13. Turn the ignition switch to LOCK (0).
  14. Reinstall the radiator fan relay.
  15. Jump the SCS line with the HDS.
    NOTE: This step must be done to protect the powertrain control module (PCM) from damage.
  16. Disconnect PCM connector A (49P).
  17. Connect PCM connector A (49P) terminal No. 4 to body ground with a jumper wire.
    Fig 4: Identifying PCM Connector A (49P) Terminal No. 4 Connection With Body Ground Using Jumper Wire
    G08090259Courtesy of AMERICAN HONDA MOTOR CO., INC.
  18. Turn the ignition switch to ON (II).

    Do the A/C condenser and radiator fans run on low? 

    YES  -Check for loose wires or poor connections at PCM connector A (49P) terminal No. 4. If the connections is good, substitute a known-good PCM (see SUBSTITUTING THE PCM ), and recheck. If the symptom/indication goes away, replace the original PCM(see PCM REPLACEMENT ).

    NO  -Repair an open in the wire between the radiator fan relay and the PCM.

  19. Disconnect the jumper wire.
  20. Reinstall the radiator fan relay.
  21. Disconnect the radiator fan motor 2P connector.
  22. Turn the ignition switch to ON (II), then set the A/C button and fan control button ON.
  23. Measure the voltage between radiator fan motor 2P connector terminal No. 2 and body ground.
    Fig 5: Measuring Voltage Between Radiator Fan Motor 2P Connector Terminal No. 2 And Body Ground
    G08090260Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Go to step 24.

    NO  -Repair an open in the wire between the radiator fan relay and the radiator fan motor.

  24. Set the A/C button and fan control button OFF, then turn the ignition switch to LOCK (0).
  25. Reconnect the radiator fan motor 2P connector.
  26. Connect radiator fan motor 2P connector terminal No. 1 to body ground with a jumper wire.
    Fig 6: Identifying Radiator Fan Motor 2P Connector Terminal No. 1 Connection With Body Ground Using Jumper Wire
    G08090261Courtesy of AMERICAN HONDA MOTOR CO., INC.
  27. Turn the ignition switch to ON (II), then set the A/C button and fan control button ON.

    Does the radiator fan run? 

    YES  -Go to step 28.

    NO  -Replace the radiator fan motor (see RADIATOR AND FAN REPLACEMENT ).

  28. Set the A/C button and fan control button OFF, then turn the ignition switch to LOCK (0).
  29. Disconnect the jumper wire.
  30. Remove the fan control relay from the under-hood fuse/relay box, and test it (see POWER RELAY TEST ).

    Is the relay OK? 

    YES  -Go to step 31.

    NO  -Replace the fan control relay.

  31. Turn the ignition switch to ON (II), then set the A/C button and fan control button ON.
  32. Measure the voltage between fan control relay 5P socket terminal No. 1 and body ground.
    Fig 7: Measuring Voltage Between Fan Control Relay 5P Socket Terminal No. 1 And Body Ground
    G08090262Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Go to step 33.

    NO  -Repair an open in the wire between the radiator fan motor and the fan control relay.

  33. Set the A/C button and fan control button OFF, then turn the ignition switch to LOCK (0).
  34. Disconnect the A/C condenser fan motor 2P connector.
  35. Check for continuity between fan control relay 5P socket terminal No. 4 and A/C condenser fan motor 2P connector terminal No. 2.
    Fig 8: Checking Continuity Between Fan Control Relay 5P Socket Terminal No. 4 And A/C Condenser Fan Motor 2P Connector Terminal No. 2
    G08090263Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step 36.

    NO  -Repair an open in the wire between the fan control relay and the A/C condenser fan motor.

  36. Check for continuity between A/C condenser fan motor 2P connector terminal No. 1 and body ground.
    Fig 9: Checking Continuity Between A/C Condenser Fan Motor 2P Connector Terminal No. 1 And Body Ground
    G08090264Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Replace the A/C condenser fan motor (see RADIATOR AND FAN REPLACEMENT ).

    NO  -Check for an open in the wire between the A/C condenser fan motor and body ground. If the wire is OK, check for poor ground at G201 (see CONNECTOR TO FUSE/RELAY BOX INDEX ).

  37. Turn the ignition switch to LOCK (0).
  38. Remove A/C diode A from the relay block.
  39. Using the diode setting on a DVOM, check for current flow in both directions between A/C diode A terminals No. 1 and No. 2.
    Fig 10: Checking Current Flow In Directions Between A/C Diode A Terminals No. 1 And No. 2 Using Diode Setting On DVOM
    G08090265Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there current flow in only one direction? 

    YES  -Go to step 40.

    NO  -Replace A/C diode A.

  40. Turn the ignition switch to ON (II).
  41. Measure the voltage between A/C diode A 2P socket terminal No. 2 and body ground.
    Fig 11: Measuring Voltage Between A/C Diode A 2P Socket Terminal No. 2 And Body Ground
    G08090266Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Replace the under-hood fuse/relay box (see REMOVAL AND INSTALLATION ).

    NO  -Repair an open in the wire between the No. 36 (10 A) fuse in the under-dash fuse/relay box and A/C diode A.

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