Headlight Dimmer Switch Circuit [09/2013 - ]: Procedure

1. Using the Techstream, read the Data List. Refer to DATA LIST / ACTIVE TEST [09/2013 - ] .
   MAIN BODY
   
   

   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	-
   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	-

   OK

   The display is as specified in the normal condition column.

NG → See step   2 

OK → See step   4 

1. Remove the headlight dimmer switch assembly. Refer to REMOVAL [09/2013 - ] .
2. Inspect the headlight dimmer switch assembly. Refer to INSPECTION [09/2013 - ] .

NG → See step   5 

OK: Go to next step 

1. Disconnect the E12 headlight dimmer switch assembly connector.
2. Disconnect the E15, E17 and IJ main body ECU connectors.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   E12-17 (HF) - E15-22 (HF)	Always	Below 1 Ω
   E12-11 (HU) - IJ-4 (HU)
   E12-19 (A) - E17-18 (A)
   E12-20 (H) - E17-12 (HEAD)
   E12-18 (T) - E15-21 (TAIL)
   E12-12 (EL) - Body ground
   E12-17 (HF) - Body ground	Always	10 kΩ or higher
   E12-11 (HU) - Body ground
   E12-19 (A) - Body ground
   E12-20 (H) - Body ground
   E12-18 (T) - Body ground

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)