68-12

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. Start the engine.

2. Check the BRAKE PRESSURE in the VSA DATA LIST with the HDS.

NOTE: Do not press the brake pedal.

Is there 10 MPa or more?

YES -

Check the brake pedal height Adjustments. If the brake pedal height is OK, go to step 16.

NO -

Go to step 3.

3. Check the BRAKE SWITCH in the VSA DATA LIST with the HDS while moving 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.�

NO -

Go to step 4.

4. Check the BRAKE SWITCH in the VSA DATA LIST with the HDS, and disconnect the brake pedal position switch 4P connector.

Does the indicator change from ON to OFF?

YES -

Replace the brake pedal position switch Testing and Inspection.�

NO -

Go to step 5.

5. Turn the ignition switch to LOCK (0).

6. Short the SCS line with the HDS.

7. Disconnect PCM connector A (49P) Service and Repair.

8. Turn the ignition switch to ON (II).

9. Measure the voltage between brake pedal position switch 4P connector terminal No. 2 and body ground.





Is there 0.1 V or more?

YES -

Repair a short to power in the wire between the PCM and the brake pedal position switch.�

NO -

Go to step 10.

10. Turn the ignition switch to LOCK (0).

11. Reconnect all connectors.

12. Update the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM.

13. Clear the DTC with the HDS.

14. Turn the ignition switch to LOCK (0) and then back to ON (II).

15. Check for DTCs with the HDS.

Is DTC 68-12 indicated?

YES -

Check for loose terminals in the PCM connector A (49P). If the PCM was updated, substitute a known-good PCM, then retest. If the PCM was substituted, go to step 1.

NO -

The troubleshooting is complete.�

16. Update the VSA modulator-control unit if it does not have the latest software Testing and Inspection. If the unit already has the latest software, substitute a known-good VSA modulator-control unit Service and Repair.

17. Turn the ignition switch to LOCK (0) and then back to ON (II).

18. Check for DTCs with the HDS.

Is DTC 68-12 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 Service and Repair, 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 Service and Repair. If any other DTCs are indicated, go to the indicated DTCs troubleshooting.�