Headlight Dimmer Switch Circuit [10/2014 - 09/2017]: Procedure

1. Using the Techstream, read the Data List.

   Refer to DATA LIST / ACTIVE TEST [10/2014 - ]

   Body Electrical > Main Body > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   Dimmer SW	Headlight dimmer switch high position signal	ON or OFF	ON: Headlight dimmer switch in high or high flash position OFF: Headlight dimmer switch in low position	-
   Passing Light SW	Headlight dimmer switch high flash position (pass) signal	ON or OFF	ON: Headlight dimmer switch in high flash position OFF: Headlight dimmer switch not in high flash position	-
   Front Fog Light SW	Front fog light switch signal	ON or OFF	ON: Front fog light switch on OFF: Front fog light switch off	-
   Auto Light SW	Headlight dimmer switch AUTO position signal	ON or OFF	ON: Headlight dimmer switch in AUTO position OFF: Headlight dimmer switch not in AUTO position	-
   Head Light SW (Head)	Headlight dimmer switch head position signal	ON or OFF	ON: Headlight dimmer switch in head position OFF: Headlight dimmer switch not in head position	-
   Head Light SW (Tail)	Headlight dimmer switch tail position signal	ON or OFF	ON: Headlight dimmer switch in tail or head position OFF: Headlight dimmer switch in neither tail nor head position	-

   Body Electrical > Main Body > Data List 

   Tester Display
   Dimmer SW
   Passing Light SW
   Front Fog Light SW
   Auto Light SW
   Head Light SW (Head)
   Head Light SW (Tail)

   Result

   Proceed to
   OK
   NG

Result: 

OK 

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [10/2014 - 09/2017] 

Result: 

NG 

See step  2

1. Remove the headlight dimmer switch assembly.

   Refer to REMOVAL [10/2014 - 05/2019]

2. Inspect the headlight dimmer switch assembly.

   Refer to INSPECTION [10/2014 - 07/2020]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE HEADLIGHT DIMMER SWITCH ASSEMBLY. Refer to  REMOVAL [10/2014 - 05/2019] 

Result: 

OK 

See step  3

1. Disconnect the I126 headlight dimmer switch assembly connector.
2. Disconnect the I48 main body ECU (multiplex network body ECU) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   I48-22 (TAIL) - I126-18 (T)	Always	Below 1 Ω
   I48-12 (HEAD) - I126-19 (H)	Always	Below 1 Ω
   I48-8 (A) - I126-20 (A)	Always	Below 1 Ω
   I48-24 (HU) - I126-14 (HU)	Always	Below 1 Ω
   I48-10 (HF) - I126-17 (HF)	Always	Below 1 Ω
   I48-26 (FFOG) - I126-9 (BFG)	Always	Below 1 Ω
   I126-8 (LFG) - Body ground	Always	Below 1 Ω
   I126-15 (EL) - Body ground	Always	Below 1 Ω
   I48-22 (TAIL) - Body ground	Always	10 kΩ or higher
   I48-12 (HEAD) - Body ground	Always	10 kΩ or higher
   I48-8 (A) - Body ground	Always	10 kΩ or higher
   I48-24 (HU) - Body ground	Always	10 kΩ or higher
   I48-10 (HF) - Body ground	Always	10 kΩ or higher
   I48-26 (FFOG) - 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 [10/2014 - 05/2019] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR