Headlight Dimmer Switch Circuit: Procedure
- READ VALUE USING TECHSTREAM (HEADLIGHT DIMMER SWITCH)
- Using the Techstream, read the Data List. Refer to DATA LIST / ACTIVE TEST
.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- 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- OK
The display is as specified in the normal condition column.
NG → See step 2
OK → See step 4
- Using the Techstream, read the Data List. Refer to DATA LIST / ACTIVE TEST
.
- INSPECT HEADLIGHT DIMMER SWITCH ASSEMBLY
- Remove the headlight dimmer switch. Refer to REMOVAL .
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Switch Condition Specified Condition 4 (BFG) - 3 (LFG) Fog light switch on Below 1 Ω 11 (HU) - 12 (EL) Headlight dimmer switch high position Below 1 Ω Headlight dimmer switch high flash position 17 (HF) - 12 (EL) Headlight dimmer switch high flash position Below 1 Ω 18 (T) - 12 (EL) Headlight dimmer switch tail position Below 1 Ω Headlight dimmer switch head position 19 (A) - 12 (EL) Headlight dimmer switch AUTO position Below 1 Ω 20 (H) - 12 (EL) Headlight dimmer switch head position Below 1 Ω 4 (BFG) - 3 (LFG) Fog light switch off 10 kΩ or higher 18 (T) - 12 (EL) Headlight dimmer switch off 10 kΩ or higher 19 (A) - 12 (EL) 20 (H) - 12 (EL)
NG → See step 5
OK: Go to next step
- CHECK HARNESS AND CONNECTOR (HEADLIGHT DIMMER SWITCH ASSEMBLY - MAIN BODY ECU AND BODY GROUND)
- Disconnect the G31 headlight dimmer switch connector.
- Disconnect the G47 main body ECU connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition G31-4 (BFG) - G47-27 (FFOG) Always Below 1 Ω G31-11 (HU) - G47-5 (HU) Always Below 1 Ω G31-17 (HF) - G47-8 (HF) Always Below 1 Ω G31-18 (T) - G47-30 (TAIL) Always Below 1 Ω G31-19 (A) - G47-28 (A) Always Below 1 Ω G31-20 (H) - G47-29 (HEAD) Always Below 1 Ω G31-3 (LFG) - Body ground Always Below 1 Ω G31-12 (E) - Body ground Always Below 1 Ω G31-4 (BFG) - Body ground Always 10 kΩ or higher G31-11 (HU) - Body ground Always 10 kΩ or higher G31-17 (HF) - Body ground Always 10 kΩ or higher G31-18 (T) - Body ground Always 10 kΩ or higher G31-19 (A) - Body ground Always 10 kΩ or higher G31-20 (H) - Body ground Always 10 kΩ or higher
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK → See step 6
- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to PROBLEM SYMPTOMS TABLE
- REPLACE HEADLIGHT DIMMER SWITCH ASSEMBLY. Refer to REMOVAL
- REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to REMOVAL