Mirror Heater does not Operate with Rear Defogger Switch: Procedure

1. Check that the defogger operates normally.

   OK

   Defogger operates normally.

NG → GO TO APPROPRIATE DEFOGGER SYSTEM ARTICLE 

OK: Go to next step 

1. Select the ACTIVE TEST, use Techstream to generate a control command, and then check the mirror heater function.

   Front multiplex network door ECU LH, RH

   Tester Display	Test Details	Control Range	Diagnostic Note
   Mirror Heater	Mirror heater operation	OFF / ON	-

   Result

   Front multiplex network door ECU LH:

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

   Result

   Front multiplex network door ECU RH:

   Result	Proceed to
   Outer rear view mirror RH does not operate normally	C
   Outer rear view mirror RH operates normally	D

D → See step   6 

C → See step   4 

B → See step   5 

A: Go to next step 

Fig 1: Inspecting Outer Rear View Mirror Assembly LH

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

      Standard resistance

      3.6 to 4.8 Ω at 25°C (75 °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

      HINT: 

      It will take a short time for the mirror to become warm.

NG → REPLACE OUTER REAR VIEW MIRROR ASSEMBLY LH 

OK → REPLACE FRONT MULTIPLEX NETWORK DOOR ECU LH 

Fig 2: View Of Measuring Resistance Between Terminals 4 And 12 Of Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

      Standard resistance

      3.6 to 4.8 Ω at 25°C (75°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

      HINT: 

      It will take a short time for the mirror to become warm.

NG → REPLACE OUTER REAR VIEW MIRROR ASSEMBLY RH 

OK → REPLACE FRONT MULTIPLEX NETWORK DOOR ECU RH 

1. Check if the malfunction disappears when a normally functioning front multiplex network door ECU LH is installed.

   OK

   Mirror heater operates normally.

NG → REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY 

OK → REPLACE FRONT MULTIPLEX NETWORK DOOR ECU LH 

1. Check if the malfunction disappears when a normally functioning front multiplex network door ECU RH is installed.

   OK

   Mirror heater operates normally.

NG → REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY 

OK → REPLACE FRONT MULTIPLEX NETWORK DOOR ECU RH