Headlight (HI-BEAM) Circuit [08/2017 - 08/2019]: Procedure

1. Using the Techstream, perform the Active Test.

   Refer to DATA LIST / ACTIVE TEST [08/2017 - 08/2019]

   MAIN BODY
   
   

   Tester Display	Test Part	Control Range	Diagnostic Note
   Head Light Hi	Headlight dimmer relay (DIMMER)	OFF or ON	-

   OK

   Headlight dimmer relay (DIMMER) operates (high beam headlights turn on).

   Result

   Proceed to
   OK
   NG

Result: 

OK 

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [08/2017 - 08/2019] 

Result: 

NG 

See step  2

1. Remove the headlight dimmer relay (DIMMER) from the engine room relay block and junction block.
2. Inspect the headlight dimmer relay (DIMMER).

   Refer to ON-VEHICLE INSPECTION [08/2017 - ]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE HEADLIGHT DIMMER RELAY (DIMMER) 

Result: 

OK 

See step  3

1. Remove the headlight dimmer relay (DIMMER) from the engine room relay block and junction block.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Headlight Dimmer Relay [DIMMER])

2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   Headlight dimmer relay (DIMMER) terminal 1 - Body ground	Always	11 to 14 V
   Headlight dimmer relay (DIMMER) terminal 3 - Body ground	Always	11 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  4

1. Remove the headlight dimmer relay (DIMMER) from the engine room relay block and junction block.
2. Disconnect the H133 main body ECU (multiplex network body ECU) connector.
3. Disconnect the A63 headlight assembly LH connector.
4. Disconnect the A64 headlight assembly RH connector.
5. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   Headlight dimmer relay (DIMMER) terminal 2 - H133-1 (DIM)	Always	Below 1 Ω
   Headlight dimmer relay (DIMMER) terminal 5 - A63-1 (HI)	Always	Below 1 Ω
   Headlight dimmer relay (DIMMER) terminal 2 or H133-1 (DIM) - Body ground	Always	10 kΩ or higher
   Headlight dimmer relay (DIMMER) terminal 5 or A63-1 (HI) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [08/2017 - 08/2019] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR