DTC P1631-81: Communication Error from ECM to VSC Invalid Serial Data Received [11/2022 - ]: Procedure
WARNING: This page is about a different car, the 2025 Toyota Corolla Cross, 2024 Toyota Corolla Cross, and 2023 Toyota Corolla Cross. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK FOR DTCs
- Check for electronically controlled brake system DTCs.
Chassis > Brake/EPB > Trouble Codes
Chassis > Brake Booster > Trouble Codes
Result
Result Proceed to Electronically controlled brake system DTCs are not output A Electronically controlled brake system DTCs are output B
Result:
B
GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM
Refer to HOW TO PROCEED WITH TROUBLESHOOTING [11/2022 - ]
Result:
A
See step 2
- Check for electronically controlled brake system DTCs.
- CHECK FOR DTCs
- Clear the DTCs.
- Make sure that the DTC detection conditions are met.
HINT:
If the detection conditions are not met, the system cannot detect the malfunction.
- Check for DTCs.
Powertrain > Hybrid Control > Trouble Codes
Result
Result Proceed to DTC P1631-81 is not output A DTC P1631-81 is output B
Result:
A
USE SIMULATION METHOD TO CHECK
Refer to HOW TO PROCEED WITH TROUBLESHOOTING [09/2021 - ]
Result:
B
REPLACE HYBRID VEHICLE CONTROL ECU
Refer to REMOVAL [11/2022 - 12/2024] , or refer to REMOVAL [12/2024 - ]