DTC 86-31: F-CAN Communication With Gauge Control Module Malfunction

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information. (See General Troubleshooting Information ).

NOTE: Troubleshoot the fuel and emissions DTCs first.

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Turn the ignition switch to LOCK (0), then turn it to ON (II) again.
Check for DTCs with the HDS.
Is DTC 86-31 indicated?

YES - If the DTC 86-01 is indicated at the same time, do the DTC 86-01 troubleshooting (see DTC 86-01: F-CAN BUS-OFF MALFUNCTION ). If the DTC 86-01 is not indicated, go to step 5.

NO - If any other DTCs are indicated, go to the indicated DTCs troubleshooting. If DTCs are not indicated, intermittent failure, the system is OK at this time. Refer to intermittent failures troubleshooting (see Intermittent Failures ).
Turn the ignition switch to ON (II).
Do the gauge indicators come on?

YES - Go to step 6.

NO - Do the gauge control module troubleshooting (see SELF-DIAGNOSTIC FUNCTION ).
Turn the ignition switch to LOCK (0).
Disconnect the gauge control module 32P connector (see step 3 on GAUGE CONTROL MODULE REPLACEMENT ).
Disconnect the VSA modulator-control unit 36P connector (see step 3 ).

Check for continuity between the VSA modulator-control unit 36P connector terminal and gauge control module 32P connector terminal (see table).

CONNECTOR TERMINAL REFERENCE TABLE

Sign	VSA Modulator-control Unit 36P Connector Terminal	Gauge Control Module 32P Connector Terminal
F-CAN-L	No. 1	No. 29
F-CAN-H	No. 14	No. 30

Fig 1: Checking Continuity Between VSA Modulator-Control Unit 36P & Gauge Control Module 32P Connector Terminal

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Check for loose terminals in the gauge control module 32P connector. If necessary, substitute a known-good gauge control module, then go to step 1 and recheck. If no DTCs are indicated, replace the original gauge control module (see GAUGE CONTROL MODULE REPLACEMENT ). If DTC 86-31 resets, go to step 10.

NO -Repair open in the wire between the gauge control module and the VSA modulator-control unit.

Reconnect all connectors.
Update the VSA modulator-control unit if it does not have the latest software (see VSA MODULATOR-CONTROL UNIT UPDATE ).
Turn the ignition switch to LOCK (0), then turn it to ON (II) again.
Check for DTCs with the HDS.
Is DTC 86-31 indicated?

YES - Check for loose terminals in the VSA modulator-control unit 36P connector. If 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.