DTC U1331: Software Incompatibility with Body Control Module "B" [04/2013 - 09/2020]: Procedure

1. Check the main body ECU (multiplex network body ECU) part number.
   1. Check if the part number of the main body ECU (multiplex network body ECU) installed on the vehicle is correct.

      OK

      The part number is correct.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [04/2013 - ] 

Result: 

OK 

See step  2

1. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [04/2013 - 09/2020]

   Body Electrical > Blind Spot Monitor Master > Clear DTCs 

   Body Electrical > Blind Spot Monitor Slave > Clear DTCs 

2. Recheck for DTCs and check if the same DTC is output again.

   Body Electrical > Blind Spot Monitor Master > Trouble Codes 

   Body Electrical > Blind Spot Monitor Slave > Trouble Codes 

   Result

   Result	Proceed to
   No DTCs are output	A
   DTC U1331 is output ("Blind Spot Monitor Master")	B
   DTC U1331 is output ("Blind Spot Monitor Slave")	C

Result: 

A 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [04/2013 - 06/2014]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [06/2014 - 08/2015]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2015 - 10/2016]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2016 - 10/2017]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2017 - 09/2020] 

Result: 

B 

REPLACE BLIND SPOT MONITOR SENSOR LH. Refer to  REMOVAL [04/2013 - 10/2016]  , or refer to  REMOVAL [10/2016 - ] 

Result: 

C 

REPLACE BLIND SPOT MONITOR SENSOR RH. Refer to  REMOVAL [04/2013 - 10/2016]  , or refer to  REMOVAL [10/2016 - ]