VSA System

Control System DTCs

VSA DTC Troubleshooting: 68-12

DTC 68-12 : Brake Pedal Position Switch Stuck ON

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information Reading and Clearing Diagnostic Trouble Codes.

1. VSA modulator-control unit performance check:

VSA modulator-control unit performance check
-1. Start the engine.

-2. Check the BRAKE PRESSURE in the VSA DATA LIST with the HDS. Do not press the brake pedal.

Is there 10 MPa or more?
-YES- Go to step 2.
-NO- Go to step 3.

2. Brake pedal height check:

Brake pedal height check
-1. Check the brake pedal height Adjustments.

Is brake pedal height OK?
-YES- Go to step 7.
-NO- Adjust the brake pedal height.

3. Brake pedal position switch performance check 1:

Brake pedal position switch performance check 1
-1. Check the BRAKE SWITCH in the VSA DATA LIST with the HDS while pressing the brake pedal.

Does it indicate ON when the pedal is pressed, and OFF when the pedal is released?
-YES- Intermittent failure, the system is OK at this time. Refer to intermittent failures troubleshooting.
-NO- Go to step 4.

4. Brake pedal position switch performance check 2:

Brake pedal position switch performance check 2
-1. Disconnect the following connector.





-2. Check the BRAKE SWITCH in the VSA DATA LIST with the HDS.

Does the indicator change from ON to OFF?
-YES- Replace the brake pedal position switch Adjustments.
-NO- Go to step 5.

5. Shorted wire check (STOP_SW line to power):

Shorted wire check (STOP_SW line to power)
-1. Turn the ignition switch to LOCK (0).

-2. Short the SCS line with the HDS.

-3. Disconnect the following connector.





-4. Turn the ignition switch to ON (II).

-5. Measure the voltage between test points 1 and 2.









Is there 0.1 V or more?
-YES- Repair a short to power in the wire between the ECM/PCM and the brake pedal position switch.
-NO- The STOP_SW wire is OK. Go to step 6.

6. ECM/PCM check (update or substitution):

ECM/PCM check (update or substitution)
-1. Turn the ignition switch to LOCK (0).

-2. Reconnect the following connectors.





-3. Update the ECM/PCM if it does not have the latest software ECM/PCM Update, or substitute a known-good ECM/PCM Service and Repair.

-4. Clear the DTC with the HDS.

-5. Turn the ignition switch to LOCK (0), then turn it to ON (II) again.

-6. Check for DTCs with the HDS.

Is DTC 68-12 indicated?
-YES- Go to step 7.
-NO- If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM Service and Repair.

7. 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 Programming and Relearning.

-2. Turn the ignition switch to LOCK (0), then turn it to ON (II) again.

-3. Check for DTCs with the HDS.

Is DTC 68-12 indicated?
-YES- Check for loose terminals in the VSA modulator-control unit 22P connector. If the VSA modulator-control unit was updated and the symptom/indication is still present, replace the VSA modulator-control unit Service and Repair.
-NO- Troubleshooting is complete. If any other DTCs are indicated, go to the indicated DTCs troubleshooting.