DTC C0040-12
DTC C0040-12 : Brake Light Switch Failure (Stuck ON)
NOTE: Before you troubleshoot, review the general troubleshooting information - Refer to:
How to Troubleshoot the VSA System (2014 2015 2016) or
How to Troubleshoot the VSA System (2017 2018 2019 2020) .
| DTC Description | DTC | Freeze Frame |
|---|---|---|
| C0040-12 Brake Light Switch Failure (Stuck ON) |
DTC (VSA)
- Problem verification
- 1. Turn the vehicle to the ON mode.
- 2. Clear the DTC with the HDS.
- 3. Turn the vehicle to the OFF (LOCK) mode, then start the engine.
- 4. Test-drive the vehicle under these conditions:
- Vehicle speed at 9 mph (15 km/h) or more for at least 60 seconds
- Accelerator pedal pressed
- Brake pedal released
NOTE: Drive the vehicle on the road, not on a lift.
- 5. Check for DTCs with the HDS.
DTC Description DTC Freeze Frame C0040-12 Brake Light Switch Failure (Stuck ON) Is DTC C0040-12 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 - Refer to:
How to Troubleshoot the VSA System (2014 2015 2016) or
How to Troubleshoot the VSA System (2017 2018 2019 2020) .
If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.
- Brake pedal height check
- 1.Check the brake pedal height. Refer to: Brake Pedal and Brake Pedal Position Switch Adjustment
Is the brake pedal height OK?
YES
Go to step 3.
NO
- Brake pedal position switch performance check 1
- 1. Check the parameter (s) below with the HDS.
Signal Current conditions Values Unit BRAKE SWITCH Does the signal change ON and OFF when the brake pedal is pressed and released?
YES
Check for loose terminals and poor connections in the VSA modulator-control unit 38P connector. If they are OK, replace the VSA modulator-control unit .
NO
Go to step 4.
- Brake pedal position switch performance check 2
- 1. Turn the vehicle to the OFF (LOCK) mode.
- 2. Disconnect the following connector.
Brake pedal position switch 4P connector - 3. Check the parameter (s) below with the HDS.
Signal Current conditions Values Unit BRAKE SWITCH Does the indicator change from ON to OFF?
YES
Replace the brake pedal position switch .
NO
Go to step 5.
- Shorted wire check (STOP SW line to power) 1
- 1. Turn the vehicle to the OFF (LOCK) mode.
- 2. Jump the SCS line with the HDS, and wait more than 1 minute.
- 3. Disconnect the following connector.
PCM connector A (51P) - 4. Turn the vehicle to the ON mode.
- 5. Measure the voltage between test points 1 and 2.
Test condition Vehicle ON mode Brake pedal position switch 4P connector: disconnected PCM connector A (51P): disconnected Test point 1 PCM connector A (51P) No. 25 - Refer to:
PCM Connector for Inputs and Outputs (2014 2015), or
PCM Connector for Inputs and Outputs (2016), or
PCM Connector for Inputs and Outputs (2017 2018 2019 2020)Test point 2 Body ground Is there 0.1 V or more?
YES
Go to step 6.
NO
The STOP SW wire is OK. Go to step 8.
- Shorted wire check (STOP SW line to power) 2
- 1. Turn the vehicle to the OFF (LOCK) mode.
- 2.Remove the brake light relay. Refer to:
Relay and Control Unit Locations (2014 2015)
Relay and Control Unit Locations (2016)
Relay and Control Unit Locations (2017 2018 2019 2020)
- 3. Turn the vehicle to the ON mode.
- 4. Measure the voltage between test points 1 and 2.
Test condition Vehicle ON mode Brake pedal position switch 4P connector: disconnected PCM connector A (51P): disconnected Brake light relay: removed Test point 1 PCM connector A (51P) No. 25 - Refer to:
PCM Connector for Inputs and Outputs (2014 2015), or
PCM Connector for Inputs and Outputs (2016), or
PCM Connector for Inputs and Outputs (2017 2018 2019 2020)Test point 2 Body ground Is there 0.1 V or more?
YES
Repair a short to power in the wire between the brake pedal position switch and the PCM.
NO
The STOP SW wire is OK. Go to step 7.
- Shorted wire check (BRAKE DIAG line to power)
- 1. Turn the vehicle to the OFF (LOCK) mode.
- 2. Disconnect the following connector.
VSA modulator-control unit 38P connector - 3. Turn the vehicle to the ON mode.
- 4. Measure the voltage between test points 1 and 2.
Test condition Vehicle ON mode Brake pedal position switch 4P connector: disconnected PCM connector A (51P): disconnected Brake light relay: removed VSA modulator-control unit 38P connector: disconnected Test point 1 VSA modulator-control unit 38P connector No. 18 - Refer to:
VSA Modulator-Control Unit Connector for Inputs and Outputs (2014 2015), or
VSA Modulator-Control Unit Connector for Inputs and Outputs (2016), or
VSA Modulator-Control Unit Connector for Inputs and Outputs (2017 2018 2019 2020)Test point 2 Body ground Is there 0.1 V or more?
YES
Repair a short to power in the wire between the brake light relay and the VSA modulator-control unit.
NO
Replace the brake light relay - Refer to:
Relay and Control Unit Locations (2014 2015), or
- PCM check (substitution)
- 1. Turn the vehicle to the OFF (LOCK) mode.
- 2. Reconnect the following connectors.
Brake pedal position switch 4P connector PCM connector A (51P) - 3. Substitute a known-good PCM. Refer to:
PCM Removal and Installation (2014 2015) or
PCM Removal and Installation (2016 2017 2018 2019 2020)
- 4. Turn the vehicle to the ON mode.
- 5. Clear the DTC with the HDS.
- 6. Turn the vehicle to the OFF (LOCK) mode, then start the engine.
- 7. Test-drive the vehicle under these conditions:
- Vehicle speed at 9 mph (15 km/h) or more for at least 60 seconds
- Accelerator pedal pressed
- Brake pedal released
NOTE: Drive the vehicle on the road, not on a lift.
- 8. Check for DTCs with the HDS.
DTC Description DTC Freeze Frame C0040-12 Brake Light Switch Failure (Stuck ON) Is DTC C0040-12 indicated?
YES
Check for loose terminals and poor connections in the VSA modulator-control unit 38P connector. If they are OK, replace the VSA modulator-control unit .
NO
Replace the original PCM - Refer to: