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Section 37 (Immobilizer System): Troubleshooting

WARNING: This page is about a different car, the 2008 Honda Pilot, 2007 Honda Pilot, and 2006 Honda Pilot. However, it is still accessible from the selected car via links, so may be relevant.

'06-07 models 

  1. Turn the ignition switch ON (II) with a programmed key.
  2. Check to see if the immobilizer indicator comes on.

    Does the indicator come on? 

    YES  - Go to step  3.

    NO  - Go to step  12.

  3. Check the Immobilizer Indicator operation.

    Does the indicator come on for 2 seconds, then go off? 

    YES  - Go to step  4.

    NO  - Go to step  6.

  4. Try to crank the engine.

    Does the starter motor operate? 

    YES  - Go to step  5.

    NO  - Check the starter motor.

  5. Try to start the engine.

    Does the engine start? 

    YES  - Check the Status Log in the immobilizer info with the HDS. (see Status Log  ).

    NO  - Go to step  25.

  6. Check to see if the immobilizer indicator comes on and blinks.

    Does the indicator blink? 

    YES  - Go to step  25.

    NO  - Go to step  7.

  7. Disconnect the 7P connector from the immobilizer control unit-receiver.
  8. Check to see if the immobilizer indicator goes off.

    Does the indicator go off? 

    YES  - Substitute a known-good immobilizer control unit-receiver and/or PCM.

    NO  - Go to step  9.

  9. Turn the ignition switch OFF.
  10. Remove the gauge control module and disconnect its connector A (20P) (see GAUGE CONTROL MODULE REPLACEMENT ).
  11. Check for continuity between the immobilizer control unit-receiver 7P connector No. 5 (IMOARM) terminal and body ground.
    Fig 1: Checking Continuity Between Immobilizer Control Unit-Receiver 7P Connector No. 5 (IMOARM) Terminal & Body Ground
    G04247296Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Repair a short in the wire.

    NO  - Faulty immobilizer indicator, replace the gauge control module.

  12. Try to start the engine.

    Does the engine start? 

    YES  - Go to step  13.

    NO  - Go to step  18.

  13. Turn the ignition switch OFF.
  14. Disconnect the 7P connector from the immobilizer control unit-receiver.
  15. Check for voltage between the immobilizer control unit-receiver 7P connector No. 7 (+B) terminal and body ground.
    Fig 2: Checking Voltage Between Immobilizer Control Unit-Receiver 7P Connector No. 7 (+B) Terminal & Body Ground
    G04247297Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  - Go to step  16.

    NO  - Faulty No. 13 (7.5 A) fuse in the passenger's under-dash fuse/relay box. If the fuse is OK, check for an open in the wire between the immobilizer control unit-receiver and passenger's under-dash fuse/relay box.

  16. Remove the gauge control module and disconnect its connector A (20P) (see GAUGE CONTROL MODULE REPLACEMENT ).
  17. Check for continuity between the immobilizer control unit-receiver 7P connector No. 5 (IMOARM) terminal and gauge control module connector A (20P) No. 9 terminal.
    Fig 3: Checking Continuity Between Immobilizer Control Unit-Receiver 7P Connector No. 5 (IMOARM) Terminal & Gauge Control Module Connector A (20P) No. 9 Terminal
    G04247298Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Faulty immobilizer indicator, replace the gauge control module.

    NO  - Repair an open in the wire

  18. Turn the ignition switch OFF.
  19. Disconnect the 7P connector from the immobilizer control unit-receiver.
  20. Turn the ignition switch ON (II).
  21. Measure the voltage between the immobilizer control unit-reciver 7P connector No. 6 (IG1) terminal and body ground.
    Fig 4: Measuring Voltage Between Immobilizer Control Unit-Reciver 7P Connector No. 6 (IG1) Terminal And Body Ground
    G04247299Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  - Go to step  22.

    NO  - Faulty No. 1 (15 A) fuse in the driver's under-dash fuse/relay box. If the fuse is OK, check for an open in the wire between the immobilizer control unit-receiver and under-hood fuse/relay box and check the PGM-FI main relay 1 (see POWER RELAY TEST ).

  22. Turn the ignition switch OFF.
  23. Jump the SCS line with the HDS, then disconnect PCM connector A (44P) (see HOW TO SUBSTITUTE THE PCM ).
  24. Check for continuity between the immobilizer control unit-receiver 7P connector No. 1 (LG3) terminal and PCM connector A (44P) No. 22 terminal.
    Fig 5: Checking Continuity Between Immobilizer Control Unit-Receiver 7P Connector No. 1 (LG3) Terminal & PCM Connector A (44P) No. 22 Terminal
    G04247300Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Substitute a known-good immobilizer control unit-receiver and/or PCM.

    NO  - Repair an open in the wire.

  25. Turn the ignition switch OFF.
  26. Connect the HDS to the data link connector.
  27. Turn the ignition switch ON (II).
  28. Look at the System Check in the immobilizer info with the HDS (see SYSTEM CHECK  ).

    Is the immobilizer system normal? 

    YES  - Go to TROUBLESHOOTING  .

    NO  - Go to step  29.

  29. Verify the System Check display on the HDS for the following information:
    • Harness short from the PCM to the immobilizer control unit-receiver. (IMOCD line short)
    • The communication was not good between the PCM and the immobilizer control unit-receiver by the battery voltage low.
    • The communication was not good between the immobilizer control unit-receiver and the PCM by influence of some noise.
    • Immobilizer control unit-receiver failure.
    • PCM failure.

    Does the HDS display any of the above information? 

    YES  - Go to step  30.

    NO  - Go to step  34.

  30. Turn the ignition switch OFF.
  31. Disconnect the 7P connector from the immobilizer control unit-receiver.
  32. Jump the SCS line with the HDS, then disconnect PCM connector A (44P) (see HOW TO SUBSTITUTE THE PCM ).
  33. Check for continuity between the immobilizer control unit-receiver 7P connector No. 2 (IMOCD) terminal and body ground.
    Fig 6: Checking Continuity Between Immobilizer Control Unit-Receiver 7P Connector No. 2 (IMOCD) Terminal & Body Ground
    G04247301Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Repair a short in the wire.

    NO  - Substitute a known-good immobilizer control unit-receiver and/or PCM.

  34. Verify the System Check display on the HDS for the following information:
    • Blown fuse.
    • Harness open from the PCM and the immobilizer control unit-receiver.
    • The communication was not good between the PCM and the immobilizer control unit-receiver by the battery voltage low.
    • The communication was not good between the immobilizer control unit-receiver and the PCM by influence of some noise.
    • Immobilizer control unit-receiver failure.
    • PCM failure.

    Does the HDS display any of the above information? 

    YES  - Go to step  35.

    NO  - Check the Possible Failures shown on the System Check display (see SYSTEM CHECK  ).

  35. Turn the ignition switch OFF.
  36. Disconnect the 7P connector from the immobilizer control unit-receiver.
  37. Jump the SCS line with the HDS, then disconnect PCM connector A (44P) (see HOW TO SUBSTITUTE THE PCM ).
  38. Check for continuity between the immobilizer control unit-receiver 7P connector No. 2 (IMOCD) terminal and PCM connector A (44P) No. 44 terminal.
    Fig 7: Checking Continuity Between Immobilizer Control Unit-Receiver 7P Connector No. 2 (IMOCD) Terminal & PCM Connector A (44P) No. 44 Terminal
    G04247302Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Substitute a known-good immobilizer control unit-receiver and/or PCM.

    NO  - Repair an open in the wire.

'08 model 

  1. Turn the ignition switch ON (II) with a programmed key.
  2. Check to see if the immobilizer indicator comes on.

    Does the indicator come on? 

    YES  - Go to step  3.

    NO  - Go to step  12.

  3. Check the Immobilizer Indicator operation.

    Does the indicator come on for 2 seconds, then go off? 

    YES  - Go to step  4.

    NO  - Go to step  6.

  4. Try to crank the engine.

    Does the starter motor operate? 

    YES  - Go to step  5.

    NO  - Check the starter motor.

  5. Try to start the engine.

    Does the engine start? 

    YES  - Check the Status Log in the immobilizer info with the HDS. (see Status Log  ).

    NO  - Go to step  25.

  6. Check to see if the immobilizer indicator comes on and blinks.

    Does the indicator blink? 

    YES  - Go to step  25.

    NO  - Go to step  7.

  7. Disconnect the 7P connector from the immobilizer control unit-receiver.
  8. Check to see if the immobilizer indicator goes off.

    Does the indicator go off? 

    YES  - Substitute a known-good immobilizer control unit-receiver and/or PCM.

    NO  - Go to step  9.

  9. Turn the ignition switch OFF.
  10. Remove the gauge control module and disconnect its connector A (20P) (see GAUGE CONTROL MODULE REPLACEMENT ).
  11. Check for continuity between the immobilizer control unit-receiver 7P connector No. 5 (IMOARM) terminal and body ground.
    Fig 8: Checking Continuity Between Immobilizer Control Unit-Receiver 7P Connector No. 5 (IMOARM) Terminal & Body Ground
    G04247296Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Repair a short in the wire.

    NO  - Faulty immobilizer indicator, replace the gauge control module.

  12. Try to start the engine.

    Does the engine start? 

    YES  - Go to step  13.

    NO  - Go to step  18.

  13. Turn the ignition switch OFF.
  14. Disconnect the 7P connector from the immobilizer control unit-receiver.
  15. Measure the voltage between the immoblizer control unit-receiver 7P connector No. 7 (+B) terminal and body ground.
    Fig 9: Measuring Voltage Between Immoblizer Control Unit-Receiver 7P Connector No. 7 (+B) Terminal And Body Ground
    G04247297Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  - Go to step  16.

    NO  - Faulty No. 13 (7.5 A) fuse in the passenger's under-dash fuse/relay box. If the fuse is OK, check for an open in the wire between the immobilizer control unit-receiver and passenger's under-dash fuse/relay box.

  16. Remove the gauge control module and disconnect its connector A (20P) (see GAUGE CONTROL MODULE REPLACEMENT ).
  17. Check for continuity between the immobilizer control unit-receiver 7P connector No. 5 (IMOARM) terminal and gauge control module connector A (20P) No. 9 terminal.
    Fig 10: Checking Continuity Between Immobilizer Control Unit-Receiver 7P Connector No. 5 (IMOARM) Terminal & Gauge Control Module Connector A (20P) No. 9 Terminal
    G04247298Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Faulty immobilizer indicator, replace the gauge control module.

    NO  - Repair an open in the wire

  18. Turn the ignition switch OFF.
  19. Disconnect the 7P connector from the immobilizer control unit-receiver.
  20. Turn the ignition switch ON (II).
  21. Measure the voltage between the immobilizer control unit-reciver 7P connector No. 6 (IG1) terminal and body ground.
    Fig 11: Measuring Voltage Between Immobilizer Control Unit-Reciver 7P Connector No. 6 (IG1) Terminal And Body Ground
    G04247299Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  - Go to step  22.

    NO  - Faulty No. 1 (15 A) fuse in the driver's under-dash fuse/relay box. If the fuse is OK, check for an open in the wire between the immobilizer control unit-receiver and under-hood fuse/relay box and check the PGM-FI main relay 1 (see POWER RELAY TEST ).

  22. Turn the ignition switch OFF.
  23. Jump the SCS line with the HDS, then disconnect PCM connector A (44P) (see HOW TO SUBSTITUTE THE PCM ).
  24. Check for continuity between the immobilizer control unit-receiver 7P connector No. 1 (LG3) terminal and PCM connector A (44P) No. 22 terminal.
    Fig 12: Checking Continuity Between Immobilizer Control Unit-Receiver 7P Connector No. 1 (LG3) Terminal & PCM Connector A (44P) No. 22 Terminal
    G04247300Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Go to step 25.

    NO  - Repair an open in the wire.

  25. Check for continuity between the imoes 5P connector No. 1 (LG3) terminal and PCM connector A (44P) No. 22 (LG3) terminal.
    Fig 13: Checking For Continuity Between Imoes 5P Connector No. 1 (LG3) Terminal And Pcm Connector A (44P) No. 22 (LG3) Terminal
    G00465103Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Substitute a known-good immboilizer control unit-receiver and/or imoes unit, and recheck..

    NO  - Repair an open in the wire.

  26. Turn the ignition switch OFF.
  27. Connect the HDS to the data link connector.
  28. Turn the ignition switch ON (II).
  29. Look at the System Check in the immobilizer info with the HDS (see SYSTEM CHECK  ).

    Is the immobilizer system normal? 

    YES  - Go to TROUBLESHOOTING  .

    NO  - Go to step  29.

  30. Verify the System Check display on the HDS for the following information:
    • Harness short from the PCM to the immobilizer control unit-receiver. (IMOCD line short)
    • The communication was not good between the PCM and the immobilizer control unit-receiver by the battery voltage low.
    • The communication was not good between the immobilizer control unit-receiver and the PCM by influence of some noise.
    • Immobilizer control unit-receiver failure.
    • PCM failure.

    Does the HDS display any of the above information? 

    YES  - Go to step  30.

    NO  - Go to step  34.

  31. Turn the ignition switch OFF.
  32. Disconnect the 7P connector from the immobilizer control unit-receiver.
  33. Jump the SCS line with the HDS, then disconnect PCM connector A (44P) (see HOW TO SUBSTITUTE THE PCM ).
  34. Check for continuity between the immobilizer control unit-receiver 7P connector No. 2 (IMOCD) terminal and body ground.
    Fig 14: Checking Continuity Between Immobilizer Control Unit-Receiver 7P Connector No. 2 (IMOCD) Terminal & Body Ground
    G04247301Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Repair a short to ground in the wire.

    NO  - Go to step 35.

  35. Disconnect the imoes unit 5P connector.
  36. Check for continuity between the imoes unit 5P connector No. 2 (IMOCD) terminal and body ground.
    Fig 15: Checking For Continuity Between Imoes Unit 5P Connector No. 2 (IMOCD) Terminal And Body Ground
    G00465104Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Repair short to ground in the wire.

    NO  - Substitute a known-good imoes unit, PCM and/or immobilizer control unit-receiver, and recheck.

  37. Verify the System Check display on the HDS for the following information:
    • Blown fuse.
    • Harness open from the PCM and the immobilizer control unit-receiver.
    • The communication was not good between the PCM and the immobilizer control unit-receiver by the battery voltage low.
    • The communication was not good between the immobilizer control unit-receiver and the PCM by influence of some noise.
    • Immobilizer control unit-receiver failure.
    • PCM failure.

    Does the HDS display any of the above information? 

    YES  - Go to step  35.

    NO  - Check the Possible Failures shown on the System Check display (see SYSTEM CHECK  ).

  38. Turn the ignition switch OFF.
  39. Disconnect the 7P connector from the immobilizer control unit-receiver.
  40. Jump the SCS line with the HDS, then disconnect PCM connector A (44P) (see HOW TO SUBSTITUTE THE PCM ).
  41. Check for continuity between the immobilizer control unit-receiver 7P connector No. 2 (IMOCD) terminal and PCM connector A (44P) No. 44 terminal.
    Fig 16: Checking Continuity Between Immobilizer Control Unit-Receiver 7P Connector No. 2 (IMOCD) Terminal & PCM Connector A (44P) No. 44 Terminal
    G04247302Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Go to step 42.

    NO  - Repair an open in the wire.

  42. Check for continuity between the imoes unit 5P connector No. 2 (IMOCD (S-Net)) terminal and PCM connector A (44P) No. 44 (IMOCD) terminal.
    Fig 17: Checking For Continuity Between Imoes Unit 5P Connector No. 2 (IMOCD (S-Net)) Terminal And PCM Connector A (44P) No. 44 (IMOCD) Terminal
    G00465105Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Substitute a known-good imoes unit and/or immoblizer control unit-receiver, and recheck the system. If the imoes unit and/or immobilizer control unit-receiver is OK, substitute a known-good PCM, and recheck.

    NO  - Repair an open in the wire.

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