2012 Honda Insight BaseFACTORY OEM SERVICE PROCEDURE

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 HOW TO USE THE HDS (HONDA DIAGNOSTIC SYSTEM) ).
  1. Turn the ignition switch to ON (II).
  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).
  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).
  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 .

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.