DTC B237C-19: Left Door Mirror Heater Circuit Current Above Threshold [11/2023 - ]: Procedure

1. Clear the DTCs.

   Body Electrical > Mirror L > Clear DTCs 

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  2

1. Operate the door mirror heater.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  3

1. Check for DTCs.

   Body Electrical > Mirror L > Trouble Codes 

   Result

   Result	Proceed to
   B237C-19 is output	A
   B237C-19 is not output	B

Result: 

B 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - ] 

Result: 

A 

See step  4

Refer to INSPECTION [12/2019 - ]

Result

Result: 

NG 

REPLACE OUTER MIRROR LH. Refer to  REMOVAL [12/2019 - ] 

Result: 

OK 

See step  5

Pre-procedure1

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the z17 outer mirror control ECU assembly LH connector.
2. Disconnect the F outer mirror LH connector.

   Procedure1

3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   z17-4 (+) - F-1 (HTR+)	Always	Below 1 Ω
   z17-12 (-) - F-2 (H/T-)	Always	Below 1 Ω
   z17-4 (+) or F-1 (HTR+) - Body ground	Always	10 kΩ or higher
   z17-12 (-) or F-2 (H/T-) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

   Post-procedure1

4. None

Result: 

OK 

REPLACE OUTER MIRROR CONTROL ECU ASSEMBLY LH. Refer to  REMOVAL [12/2019 - ] 

Result: 

NG 

REPLACE OUTER REAR VIEW MIRROR ASSEMBLY LH. Refer to  REMOVAL [11/2023 - ]