Mirror Heater does not Operate with Rear Defogger Switch: Procedure

1. Check that the front deicer function operates normally.

   OK

   Front deicer function operates normally.

NG → GO TO AIR CONDITIONING SYSTEM 

OK: Go to next step 

1. Select the Active Test, use the Techstream to generate a control command, and then check the mirror heater function.
   TESTER DISPLAY
   
   

   Tester Display	Test Part	Diagnostic Note
   Mirror Heater	Mirror defogger operation ON / OFF	-

   RESULT
   
   

   Result	Proceed to
   Outer rear view mirror LH does not operate normally	A
   Outer rear view mirror RH does not operate normally	A
   Outer rear view mirror LH operates normally	B
   Outer rear view mirror RH operates normally	C

C → REPLACE MULTIPLEX NETWORK DOOR ECU FRONT RH (FRONT PASSENGER DOOR ECU) 

B → REPLACE MULTIPLEX NETWORK DOOR ECU FRONT LH (DRIVER DOOR ECU) 

A: Go to next step 

Fig 1: Inspecting Outer Rear View Mirror Sub-Assembly LH Or RH (Mirror Heater)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Check the operation of the mirror heater.
   1. Measure the resistance between terminals 4 and 12 of the connector.

      Standard resistance

      3.57 to 4.83 Ω at 25°C (77°F)

   2. Apply battery voltage and check the mirror heater operation.

      OK

      Measurement Condition	Specified Condition
      Battery positive (+) → Terminal 4 Battery negative (-) → Terminal 12	Mirror becomes warm

C → REPLACE OUTER REAR VIEW MIRROR SUB-ASSEMBLY RH 

B → REPLACE OUTER REAR VIEW MIRROR SUB-ASSEMBLY LH 

A: Go to next step 

Fig 2: Identifying Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the R14 or R15 mirror connector.
2. Disconnect the D19 or P11 ECU connector.
3. Measure the resistance of the wire harness side connectors.

   Standard resistance

   for Driver side 

   for Front passenger side 

   Tester Connection	Specified Condition
   R14-4 - D19-13 (HTR+)	Below 1 Ω
   R14-12 - D19-22 (HTR-)	Below 1 Ω

   Tester Connection	Specified Condition
   R15-4 - P11-13 (HTR+)	Below 1 Ω
   R15-12 - P11-22 (HTR-)	Below 1 Ω

   RESULT
   
   

   Result	Proceed to
   Driver side is not as specified	A
   Front passenger side is not as specified	A
   Driver side is as specified	B
   Front passenger side is as specified	C

C → REPLACE MULTIPLEX NETWORK DOOR ECU FRONT RH 

B → REPLACE MULTIPLEX NETWORK DOOR ECU FRONT LH 

A → REPAIR OR REPLACE HARNESS OR CONNECTOR