Manufacturer Code Charts: 138

VSA DTC Troubleshooting: 138

DTC 138:

Brake Pedal Position Switch Malfunction

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

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

2. Check for DTCs with the HDS.

Is DTC 86 indicated with DTC 138 at the same time?

YES -

Do the DTC 86 troubleshooting 86.�

NO -

Go to step 3.

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

4. Check the No. 11 (15 A) fuse in the main under-hood fuse box.

Is the fuse blown?

YES -

Replace the fuse, and recheck. If the fuse is blown, check for a short to body ground in this fuse circuit.

NO -

Reinstall the checked fuse, then go to step 5.

5. Disconnect the brake pedal position switch 4P connector.

6. Measure the voltage between brake pedal position switch 4P connector terminal No. 1 and body ground.





Is there battery voltage?

YES -

Go to step 7.

NO -

Repair an open in the wire between the No. 11 (15 A) fuse in the main under-hood fuse box and the brake pedal position switch.�

7. Short the SCS line with the HDS.

8. Disconnect the PCM connector A (49P).

9. Check for continuity between brake pedal position switch 4P connector terminal No. 2 and PCM connector A (49P) terminal No. 8.





Is there continuity?

YES -

Go to step 10.

NO -

Repair an open in the wire between the PCM and the brake pedal position switch.�

10. Reconnect all connectors.

11. Do the brake pedal position switch test Testing and Inspection.

Is the switch OK?

YES -

Go to step 12.

NO -

Replace the brake pedal position switch Adjustments.�

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

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

14. Clear the DTC with the HDS.

15. Start the engine, then press the brake pedal slowly and hard.

16. Check for DTCs with the HDS.

Is DTC 138 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 17.

NO -

If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM Service and Repair.�

17. Substitute a known-good brake pedal position switch Adjustments.

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

19. Clear the DTC with the HDS.

20. Start the engine, then press the brake pedal firmly.

Is DTC 138 indicated?

YES -

Check for loose terminals in the brake pedal position switch connector, then go to step 21.

NO -

Replace the brake pedal position switch Adjustments.�

21. 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.

22. Start the engine, then press the brake pedal slowly and hard.

23. Check for DTCs with the HDS.

Is DTC 138 indicated?

YES -

Check for loose terminals in the VSA modulator-control unit 46P connector. Check for a loose connection at G303. 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 3.

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.�