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DTC 81: 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  ).
  1. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
  2. Check for other system DTCs.

    Is another DTC indicated? 

    YES  - Do the appropriate troubleshooting for the DTC.

    NO  - Go to step 3.

  3. Clear the DTC with the HDS.
  4. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
  5. Test-drive the vehicle at 19 mph (30 km/h) or more.
    NOTE: Drive the vehicle on the road, not on a lift.
  6. Check for DTCs with the HDS.

    Is DTC 81 indicated? 

    YES  - Go to step 7.

    NO  - Intermittent failure, the system is OK at this time. Refer to INTERMITTENT FAILURES TROUBLESHOOTING .

  7. Update the VSA modulator-control unit if it does not have the latest software (see VSA MODULATOR-CONTROL UNIT UPDATE  ).
  8. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
  9. Test-drive the vehicle at 19 mph (30 km/h) or more.
    NOTE: Drive the vehicle on the road, not on a lift.
  10. Check for DTCs with the HDS.

    Is DTC 81 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 .