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DTC 86: F-CAN Communication Malfunction

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see HOW TO USE THE HDS (HONDA DIAGNOSTIC SYSTEM) ).
  1. Turn the ignition switch to ON (II).
  2. Clear the DTC with the HDS.
  3. Turn the ignition switch to LOCK (0).
  4. Start and run the engine for at least 5 seconds.
  5. Check for DTCs with the HDS.

    Is DTC 86 indicated? 

    YES  -Go to step 6.

    NO  -Check the COMMU PCM, COMMU GAUGE, and COMMU YAW RATE/G, in the VSA FREEZE DATA with the HDS. Then check the F-CAN communication lines continuity to the appropriate system or sensor and loose terminals in the appropriate system or sensor connectors.

  6. Check the COMMU PCM, COMMU GAUGE, and COMMU YAW RATE/G, in the VSA DATA LIST with the HDS.

    Is there any communication errors in the system or sensor? 

    YES  -Go to step 7.

    NO  -Go to step  22.

  7. Turn the ignition switch to LOCK (0).
  8. Short the SCS line with the HDS.
  9. Disconnect PCM connector A (49P) (see PCM REPLACEMENT ).
  10. Disconnect the VSA modulator-control unit 47P connector (see step  2).
  11. Disconnect the gauge control module 32P connector (see step 3 GAUGE CONTROL MODULE REPLACEMENT ).
  12. Disconnect the yaw rate-acceleration sensor 4P connector (see step  4).
  13. Check the F-CAN communication lines for continuity between the VSA modulator-control unit and the appropriate system or sensor (see chart below).
    Component CANL Terminal CANH Terminal
    VSA modulator-control unit 13 12
    PCM A4 A3
    Gauge Control Module 19 20
    Yaw Rate-Acceleration Sensor 2 3
    Fig 1: Checking F-CAN Communication Lines For Continuity Between VSA Modulator-Control Unit And PCM Connector Terminals
    G08093852Courtesy of AMERICAN HONDA MOTOR CO., INC.
    Fig 2: Checking F-CAN Communication Lines For Continuity Between VSA Modulator-Control Unit And Gauge Control Module Connector Terminals
    G08093853Courtesy of AMERICAN HONDA MOTOR CO., INC.
    Fig 3: Checking F-CAN Communication Lines For Continuity Between VSA Modulator-Control Unit And Yaw Rate-Acceleration Sensor Connector Terminals
    G08093854Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity on the F-CAN communication line? 

    YES  -

    • If the appropriate system or sensor is the yaw rate-acceleration sensor: go to step 14.
    • If the appropriate system or sensor is not the yaw rate-acceleration sensor: go to step  18.

    NO  -Repair an open in the appropriate line.

  14. Check for loose terminals in the yaw rate-acceleration sensor 4P connector.

    Is the yaw rate-acceleration sensor 4P connectors OK? 

    YES  -Go to step 15.

    NO  -Repair or reconnect the connector securely.

  15. Turn the ignition switch to ON (II).
  16. Measure the voltage between yaw rate-acceleration sensor 4P connector terminals No. 1 and No. 4.
    Fig 4: Measuring Voltage Between Yaw Rate-Acceleration Sensor 4P Connector Terminals No. 1 And No. 4
    G08093855Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Replace the yaw rate-acceleration sensor (see YAW RATE-ACCELERATION SENSOR REPLACEMENT ).

    NO  -Go to step 17.

  17. Measure the voltage between yaw rate-acceleration sensor 4P connector terminal No. 1 and body ground.
    Fig 5: Measuring Voltage Between Yaw Rate-Acceleration Sensor 4P Connector Terminal No. 1 And Body Ground
    G08093856Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Repair an open in the wire between the yaw rate-acceleration sensor and body ground (G502).

    NO  -Repair an open in the wire between the yaw rate-acceleration sensor and the under-dash fuse/relay box.

  18. Check for loose terminals in the appropriate system connectors.

    Are the appropriate system connectors OK? 

    YES  -Go to step 19.

    NO  -Repair or reconnect the connector securely.

  19. Reconnect all the connectors.
  20. Start and run the engine for at least 5 seconds.
  21. Check for other system DTCs with the HDS.

    Is another DTC indicated? 

    YES  -Do the appropriate DTC troubleshooting.

    NO  -Go to step 22.

  22. Update the VSA modulator-control unit if it does not have the latest software (see VSA MODULATOR-CONTROL UNIT UPDATE ).
  23. Turn the ignition switch to LOCK (0).
  24. Start and run the engine for at least 5 seconds.
  25. Check for DTCs with the HDS.

    Is DTC 86 indicated? 

    YES  -Check for loose terminals in the VSA modulator-control unit 47P connector. If the VSA modulator-control unit was updated and the symptom/indication is still present, replace the VSA modulator-control unit (see VSA MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION ).

    NO  -If the VSA modulator-control unit was updated, troubleshooting is complete. If any other DTCs are indicated, go to the indicated DTCS TROUBLESHOOTING .

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