DTC P1631-81: Communication Error from ECM to VSC Invalid Serial Data Received [04/2018 - 08/2021]: Procedure

1. Using the Techstream, check if the CAN communication system is functioning normally.

   Refer to DIAGNOSIS SYSTEM [04/2018 - 08/2020] , or refer to DIAGNOSIS SYSTEM [08/2020 - 08/2021]

   Result

   Result	Proceed to
   CAN communication system DTCs are not output	OK
   CAN communication system DTCs are output	NG

Result: 

NG 

GO TO CAN COMMUNICATION SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [04/2018 -] 

Result: 

OK 

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 

See step  3

1. Replace the hybrid vehicle control ECU.

   Refer to REMOVAL [04/2018 - 08/2021]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  4

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 

END 

Result: 

B 

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY. Refer to  COMPONENTS [04/2018 -]