DTC 81-12: VSA Modulator-Control Unit Internal Circuit Malfunction

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Turn the ignition switch to LOCK (0) and then back to ON (II).
Check for DTCs with the HDS.
Is DTC 81-12 indicated?

YES -Go to step 5.

NO -Intermittent failure, the system is OK at this time. Check for loose terminals between the steering angle sensor 5P connector and the VSA modulator-control unit 36P connector. Refer to INTERMITTENT FAILURES TROUBLESHOOTING .
Turn the ignition switch to LOCK (0).
Disconnect the steering angle sensor 5P connector (see STEERING ANGLE SENSOR REPLACEMENT ).
Disconnect the VSA modulator-control unit 36P connector (see step 3.
Turn the ignition switch to ON (II).
Measure the voltage between steering angle sensor 5P connector terminal No. 5 and body ground.

Fig 1: Measuring Voltage Between Steering Angle Sensor 5P Connector Terminal No. 5 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there 0.1 V or more?

YES -Repair a short to power in the wire between the steering angle sensor and the VSA modulator-control unit.

NO -Go to step 10.
Turn the ignition switch to LOCK (0).
Reconnect all connectors.
Update the VSA modulator-control unit if it does not have the latest software (see VSA MODULATOR-CONTROL UNIT UPDATE ). If the unit already has the latest software, substitute a known-good VSA modulator-control unit (see VSA MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION ).
Turn the ignition switch to LOCK(0) and then back to ON (II).
Check for DTCs with the HDS.
Is DTC 81-12 indicated?

YES -Check for loose terminals in the VSA modulator-control unit 36P connector. If the VSA modulator-control unit was updated, substitute a known-good VSA modulator-control unit (see VSA MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION ), then retest. If the VSA modulator-control unit was substituted, go to step 1.

NO -If the VSA modulator-control unit was updated, troubleshooting is complete. If the VSA modulator-control unit was substituted, replace the original VSA modulator-control unit (see VSA MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION ). If any other DTCs are indicated, go to the indicated DTCS TROUBLESHOOTING .