DTC P1631-81: Communication Error from ECM to VSC Invalid Serial Data Received [08/2021 -]: Procedure

1. Check for electronically controlled brake system DTCs.

   Chassis > ABS/VSC/TRAC/EPB > 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 [04/2018 -] 

Result: 

A 

See step  2

1. Clear the DTCs.

   Powertrain > Radar Cruise1 > Clear DTCs 

2. Make sure that the DTC detection conditions are met.

   HINT: 

   If the detection conditions are not met, the system cannot detect the malfunction.

3. Check for DTCs.

   Powertrain > Radar Cruise1 > 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 [04/2018 -] 

Result: 

B 

REPLACE HYBRID VEHICLE CONTROL ECU. Refer to  REMOVAL [08/2021 -]