VSA DTC Troubleshooting: 81-20
DTC 81-20: Acceleration Sensor (Inside of 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.
While doing this troubleshooting, avoid vibration or shaking of the vehicle.
The yaw rate-acceleration sensor is built into the VSA modulator-control unit.
Before troubleshooting, check the VSA modulator-control unit for proper mounting. Improper mounting of the VSA modulator-control unit may set this code.

DTC Description
DTC
Freeze Frame
81-20 Acceleration Sensor (Inside of Modulator-Control Unit) Internal Circuit Malfunction
    

1.
Problem verification:

Problem verification
?1.
Park the vehicle on a flat and level surface.

?2.
Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.

?3.
Clear the DTC with the HDS.


?4.
Turn the ignition switch to LOCK (0), then turn it to ON (II) again, or select the OFF mode, then the ON mode.

?5.
Wait for 60 seconds or more.

?6.
Check for DTCs with the HDS.
DTC Description
DTC
Freeze Frame
81-20 Acceleration Sensor (Inside of Modulator-Control Unit) Internal Circuit Malfunction
    

Is DTC 81-20 indicated?

     
YES
     
     
     
The failure is duplicated. Go to step 2.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Refer to intermittent failures troubleshooting.?
2.
VSA modulator-control unit check (update):

VSA modulator-control unit check (update)
?1.
Update the VSA modulator-control unit if it does not have the latest software.

?2.
Turn the ignition switch to LOCK (0), then turn it to ON (II) again, or select the OFF mode, then the ON mode.

?3.
Wait for 60 seconds or more.

?4.
Check for DTCs with the HDS.
DTC Description
DTC
Freeze Frame
     

Is DTC 81-20 indicated?

     
YES
     
     
     
Check for loose terminals in the VSA modulator-control unit 21P connector. If the VSA modulator-control unit was updated and the symptom/indication is still present, replace the VSA modulator-control unit.?
     
NO
     
     
     
Troubleshooting is complete. If any other DTCs are indicated, go to the indicated DTCs troubleshooting.?