Light Control Switch Circuit

LIGHTING: LIGHTING SYSTEM: Light Control Switch Circuit

Light Control Switch Circuit

DESCRIPTION

The main body ECU receives the following signals:

- Light control switch TAIL, HEAD, or AUTO signal.
- Dimmer switch HIGH or HIGH FLASH (PASS) signal.
- Front fog light switch signal.
HINT:
- When performing troubleshooting, inspect the switch that is related to the malfunction. For example, if both right and left low beam headlights do not illuminate, read the light control switch HEAD signal value only in the data list. If the value is normal, perform the headlight relay active test.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM
(a) Connect Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn Techstream on.
(d) Select the following menu items: Body Electrical / Main Body / Data List.
(e) Read the display on Techstream.

Main Body:





OK:
Normal conditions listed above are displayed.
OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
NG -- Continue to next step.
2. INSPECT HEADLIGHT DIMMER SWITCH ASSEMBLY
HINT: Testing and Inspection

OK:
Headlight dimmer switch assembly is normal.
NG -- REPLACE HEADLIGHT DIMMER SWITCH ASSEMBLY
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL J/B ASSEMBLY - SWITCH ASSEMBLY)




(a) Disconnect the E27 headlight dimmer switch assembly connector.
(b) Disconnect the E60 and E61 main body ECU connectors.
(c) Disconnect the DG instrument panel J/B connector.
(d) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY