DTC C1A31-08: Driver Monitor Camera Control System Bus Signal / Message Failure; DTC C1A31-87: Driver Monitor Camera Missing Message [11/2021 - ]: Procedure
WARNING: This page is about a different car, the 2024 Lexus LS 500h, 2023 Lexus LS 500h, and 2022 Lexus LS 500h. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK HARNESS AND CONNECTOR (DRIVER MONITOR ECU ASSEMBLY - DRIVER MONITOR CAMERA)
- Disconnect the L242 driver monitor ECU assembly connector.
- Disconnect the G177 driver monitor camera connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition L242-1 (CGND) - G177-1 (CGND) Always Below 1 Ω L242-2 (CB+) - G177-2 (CB+) Always Below 1 Ω L242-3 (CLV-) - G177-3 (CLV-) Always Below 1 Ω L242-4 (CLV+) - G177-4 (CLV+) Always Below 1 Ω L242-1 (CGND) - Body ground Always 10 kΩ or higher L242-2 (CB+) - Body ground Always 10 kΩ or higher L242-3 (CLV-) - Body ground Always 10 kΩ or higher L242-4 (CLV+) - Body ground Always 10 kΩ or higher L242-5 (SGND) - Body ground Always 10 kΩ or higher Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 2
- REPLACE DRIVER MONITOR CAMERA
- Replace the driver monitor camera with a new or known good one.
Refer to REMOVAL [11/2021 - ]
Result
Proceed to NEXT
Result:
NEXT
See step 3
- Replace the driver monitor camera with a new or known good one.
- CHECK DTC
- Clear the DTCs.
Chassis > Driver Monitor Camera Control > Clear DTCs
- Check for DTCs.
Chassis > Driver Monitor Camera Control > Trouble Codes
Result
Result Proceed to DTCs is not output. A DTCs C1A31-08 or C1A31-87 are output. B
Result:
A
END (DRIVER MONITOR CAMERA IS DEFECTIVE)
Result:
B
REPLACE DRIVER MONITOR ECU ASSEMBLY. Refer to REMOVAL [11/2021 - 10/2022] , or refer to REMOVAL [10/2022 - 10/2023] , or refer to REMOVAL [10/2023 - ]
- Clear the DTCs.