DTC B124B: Automatic High Beam System [10/2014 - 10/2015]: Procedure

1. Clear the DTCs (Refer to DTC CHECK / CLEAR [10/2014 - ] ).
2. Check for DTCs (Refer to DTC CHECK / CLEAR [10/2014 - ] ).

   OK

   DTC B124B is not output.

Result: 

OK 

USE SIMULATION METHOD TO CHECK 

(Refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2014 - 10/2015] )

Result: 

NG 

See step  2

1. Check for DTCs (Refer to DTC CHECK / CLEAR [10/2014 - ] ).

   Result

   Result	Proceed to
   Electronically controlled brake system DTCs are not output	A
   Electronically controlled brake system DTCs are output	B
   CAN communication system DTC is output	C

Result: 

B 

GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM 

(Refer to DIAGNOSTIC TROUBLE CODE CHART [10/2014 - 10/2015] )

Result: 

C 

GO TO CAN COMMUNICATION SYSTEM 

(Refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2014 - 10/2015] )

Result: 

A 

See step  3

1. Check for DTCs (Refer to DTC CHECK / CLEAR [10/2014 - ] ).

   Result

   Result	Proceed to
   Hybrid control system DTCs are not output	A
   Hybrid control system DTCs are output	B
   CAN communication system DTC is output	C

Result: 

B 

GO TO HYBRID CONTROL SYSTEM 

(Refer to DIAGNOSTIC TROUBLE CODE CHART [10/2014 - 10/2015] )

Result: 

C 

GO TO CAN COMMUNICATION SYSTEM 

(Refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2014 - 10/2015] )

Result: 

A 

See step  4

1. Replace the inner rear view mirror assembly with a new or known good one (Refer to REMOVAL [10/2014 - 10/2015] ).
2. Check for DTCs (Refer to DTC CHECK / CLEAR [10/2014 - ] ).

   OK

   DTC B124B is not output.

Result: 

OK 

END (INNER REAR VIEW MIRROR ASSEMBLY WAS DEFECTIVE) 

Result: 

NG 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) 

(Refer to REMOVAL [10/2014 - 10/2015] )