DTC 81-12: 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.
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 .