DTC C0023-12
DTC C0023-12 : Brake Diag Circuit ON Failure
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 |
|---|---|---|
| C0023-12 Brake Diag Circuit ON Failure |
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 to the ON mode.
- 4. Wait 2 seconds or more without pressing the brake pedal.
- 5. Check for DTCs with the HDS.
DTC Description DTC Freeze Frame C0023-12 Brake Diag Circuit ON Failure Is DTC C0023-12 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 light relay check
- 1. Turn the vehicle to the OFF (LOCK) mode.
- 2. Check the brake lights without pressing the brake pedal.
Are the brake lights on?
YES
Replace the brake light relay - Refer to:
Relay and Control Unit Locations (2014 2015), or
Relay and Control Unit Locations (2016), or
Relay and Control Unit Locations (2017 2018 2019 2020) .
NO
Go to step 3.
- Shorted wire check (BRAKE LAMP line) 1
- 1. Turn the vehicle to the ON mode.
- 2. Check the brake lights without pressing the brake pedal.
Are the brake lights on?
YES
Go to step 4.
NO
Go to step 5.
- Shorted wire check (BRAKE LAMP line) 2
- 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. Check the brake lights without pressing the brake pedal.
Are the brake lights on?
YES
Repair a short to ground in the wire between the brake light relay and the VSA modulator-control unit.
NO
The BRAKE LAMP wire is OK. 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 .
- Open wire check (STOP SW line)
- 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 connectors.
PCM connector A (51P) Brake pedal position switch 4P connector - 4. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode PCM connector A (51P): disconnected Brake pedal position switch 4P connector: 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 Brake pedal position switch 4P connector (female terminals) No. 1: Is there continuity?
YES
The STOP SW wire is OK. Go to step 6.
NO
Repair an open in the wire between the PCM and the brake pedal position switch.
- PCM check (substitution)
- 1. Reconnect the following connectors.
PCM connector A (51P) Brake pedal position switch 4P connector - 2. Substitute a known-good PCM.
- 3. Clear the DTC with the HDS.
- 4. Turn the vehicle to the OFF (LOCK) mode, then to the ON mode.
- 5. Wait 2 seconds or more without pressing the brake pedal.
- 6. Check for DTCs with the HDS.
DTC Description DTC Freeze Frame C0023-12 Brake Diag Circuit ON Failure Is DTC C0023-12 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: