Mirror Heater does not Operate with Rear Defogger Switch: Procedure

1. Use the Techstream to check if the multiplex communication system is functioning normally. Refer to HOW TO PROCEED WITH TROUBLESHOOTING .

   OK

   Multiplex communication DTC is not output.

NG → See step   12 

OK: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the engine switch on (IG).
3. Enter the following menus: Body Electrical / Air Conditioner / Active Test.
4. Perform an Active Test according to the display on the tester.

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

   OK

   Mirrors become warm.

NG → See step   5 

OK: Go to next step 

1. Replace the air conditioning amplifier assembly. Refer to REMOVAL

NEXT: Go to next step 

1. Turn the engine switch on (IG).
2. Check mirror heater operation.

   Result

   Result	Proceed to
   Mirrors become warm	A
   Mirrors do not operate linked with automatic wiper	B
   Mirrors do not operate linked with windshield wiper switch assembly	C

C → See step   14 

B → See step   13 

A → END (AIR CONDITIONING AMPLIFIER ASSEMBLY WAS DEFECTIVE) 

1. Select the Active Test, use the Techstream to issue a control command, and then check heater mirror relay operation.
2. Check that operation sound of the heater mirror relay can be heard.

   OK

   Operation sound of the heater mirror relay can be heard.

NG → See step   9 

OK: Go to next step 

1. Remove the heater mirror relay.
   Fig 1: Identifying Relay Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   3 - 5	When battery voltage is applied to terminals 1 and 2	Below 1 Ω
   3 - 5	When battery voltage is not applied to terminals 1 and 2	10 kΩ or higher

NG → REPLACE HEATER MIRROR RELAY 

OK: Go to next step 

1. Measure the voltage according to the table below.
   Fig 2: Identifying Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   Q52-5 - Body ground	Always	11 to 14 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (HEATER MIRROR RELAY - BATTERY) 

OK: Go to next step 

1. Disconnect the L14 and M15 connectors.
   Fig 3: Identifying Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Outer Rear View Mirror Assembly LH 

   Outer Rear View Mirror Assembly RH 

   Tester Connection	Condition	Specified Condition
   Q52-3 - M15-3 (+)	Always	Below 1 Ω
   Q52-3 - Body ground	Always	10 kΩ or higher
   M15-9 (-) - Body ground	Always	Below 1 Ω

   Tester Connection	Condition	Specified Condition
   Q52-3 - L14-3 (+)	Always	Below 1 Ω
   Q52-3 - Body ground	Always	10 kΩ or higher
   L14-9 (-) - Body ground	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (HEATER MIRROR RELAY - OUTER REAR VIEW MIRROR ASSEMBLY) 

OK → See step   15 

1. Remove the heater mirror relay.
   Fig 4: Identifying Relay Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   3 - 5	When battery voltage is applied to terminals 1 and 2	Below 1 Ω
   3 - 5	When battery voltage is not applied to terminals 1 and 2	10 kΩ or higher

NG → REPLACE HEATER MIRROR RELAY 

OK: Go to next step 

1. Measure the voltage according to the value(s) in the table below.
   Fig 5: Identifying Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   Q52-1 - Body ground	Engine switch on (IG)	11 to 14 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (HEATER MIRROR RELAY - BATTERY) 

OK: Go to next step 

1. Disconnect the J58 connector.
   Fig 6: Identifying Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   Q52-2 - J58-2 (MHTR)	Always	Below 1 Ω
   Q52-2 - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (HEATER MIRROR RELAY - A/C AMPLIFIER ASSEMBLY) 

OK → See step   16