12. Update the PCM if it does not have the latest software See: Powertrain Management/Computers and Control Systems/Engine Control
Module/Testing and Inspection/Programming and Relearning/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 See: Powertrain
Management/Computers and Control Systems/Engine Control Module/Service and Repair.?
17. Substitute a known-good brake pedal position switch See: Brakes and Traction Control/Brake Pedal Assy/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 See: Brakes and Traction Control/Brake Pedal Assy/Adjustments.?
21. Update the VSA modulator-control unit if it does not have the latest software See: Brakes and Traction Control/Antilock Brakes / Traction
Control Systems/Traction Control Module/Testing and Inspection. If the unit already has the latest software, substitute a known-good VSA
modulator-control unit See: Brakes and Traction Control/Antilock Brakes / Traction Control Systems/Traction Control Module/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 See: Brakes and Traction Control/Antilock Brakes / Traction Control
Systems/Traction Control Module/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 See: Brakes and Traction Control/Antilock Brakes / Traction Control Systems/Traction Control
Module/Service and Repair. If any other DTCs are indicated, go to the indicated DTCs troubleshooting.?
158
VSA DTC Troubleshooting: 158
DTC 158:
ECU Software Update Failure
