Lexus ES: Headlight Dimmer Switch Circuit
DESCRIPTION
The steering sensor receives the following switch information:
- Light control switch in DRL OFF*, tail, head or AUTO position
-
Dimmer switch in high, low or high flash (pass) position
- *: w/ DRL OFF Switch
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
Before replacing the main body ECU (multiplex network body ECU), refer to Registration.
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PROCEDURE
| 1. | READ VALUE USING TECHSTREAM |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Chassis / Steering Angle Sensor / Data List.
(e) Read the Data List according to the display on the Techstream.
Chassis > Steering Angle Sensor > Data List| Tester Display | Measurement Item | Range | Normal Condition | Diagnostic Note |
|---|---|---|---|---|
| Light OFF Switch | Light control switch DRL OFF position signal | OFF or ON | OFF: Light control switch not in DRL OFF position ON: Light control switch in DRL OFF position | w/ DRL OFF Switch |
| Auto Light Switch | Light control switch AUTO position signal | OFF or ON | OFF: Light control switch not in AUTO position ON: Light control switch in AUTO position | - |
| Head Light Switch (Tail) | Light control switch tail position signal | OFF or ON | OFF: Light control switch in neither tail nor head position ON: Light control switch in tail or head position | - |
| Head Light Switch (Head) | Light control switch head position signal | OFF or ON | OFF: Light control switch not in head position ON: Light control switch in head position | - |
| High Beam Main Switch | Dimmer switch high position signal | OFF or ON | OFF: Dimmer switch not in high position ON: Dimmer switch in high position | - |
| Passing Light Switch | Dimmer switch high flash position (pass) signal | OFF or ON | OFF: Dimmer switch not in high flash position ON: Dimmer switch in high flash position | - |
| Tester Display |
|---|
| Light OFF Switch |
| Auto Light Switch |
| Head Light Switch (Tail) |
| Head Light Switch (Head) |
| High Beam Main Switch |
| Passing Light Switch |
OK:
Normal conditions listed above are displayed.
| NG | .gif) | GO TO STEP 5 |
|
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| 2. | READ VALUE USING TECHSTREAM |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Body Electrical / Main Body / Data List.
(e) Read the Data List according to the display on the Techstream.
Body Electrical > Main Body > Data List| Tester Display | Measurement Item | Range | Normal Condition | Diagnostic Note |
|---|---|---|---|---|
| Head Light SW (Head) | Light control switch head position signal | OFF or ON | OFF: Light control switch not in head position ON: Light control switch in head position | - |
| Tester Display |
|---|
| Head Light SW (Head) |
OK:
Normal conditions listed above are displayed.
| OK | | PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
|
| 3. | INSPECT STEERING SENSOR |
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| *a | Component without harness connected (Steering Sensor) | - | - |
(a) Remove the steering sensor.
Click here
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| G62-7 (HEAD) - z10-4 (H) | Always | Below 1 Ω |
| NG | | REPLACE STEERING SENSOR |
|
| 4. | CHECK HARNESS AND CONNECTOR (STEERING SENSOR - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)) |
(a) Disconnect the G37 main body ECU (multiplex network body ECU) connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| G62-7 (HEAD) - G37-16 (HEAD) | Always | Below 1 Ω |
| G62-7 (HEAD) or G37-16 (HEAD) - Body ground | Always | 10 kΩ or higher |
| OK | | REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
| 5. | INSPECT TURN SIGNAL SWITCH |
(a) Remove the turn signal switch.
Click here
(b) Inspect the turn signal switch.
Click here
| NG | | REPLACE TURN SIGNAL SWITCH |
|
| 6. | INSPECT STEERING WHEEL SWITCH HOUSING |
(a) Remove the steering wheel switch housing.
Click here
(b) Inspect the steering wheel switch housing.
Click here
| OK | | REPLACE STEERING SENSOR |
| NG | | REPLACE STEERING WHEEL SWITCH HOUSING |
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