Headlight Relay Circuit

LIGHTING: LIGHTING SYSTEM: Headlight Relay Circuit
- Headlight Relay Circuit

DESCRIPTION

The headlight relay is turned ON by operating the headlight switch.

When the theft deterrent system is activated, it causes the main body ECU RH to turn the headlight relay on and off repeatedly at approximately 0.25 second intervals to flash the headlights.

In this condition, if any of the following operations is performed, the ECU to turns the headlight relay off to stop the headlight from flashing:

* Unlock the driver door with a key.

* Turn the power switch ON (ACC) or ON (IG).

* Unlock the doors with the wireless door lock control system.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM (HEADLIGHT)

(a) Select the ACTIVE TEST, use the Techstream to generate a control command, and then check that the headlight (low) illuminates.

Body (Main body ECU RH)





OK:

Headlight (low) illuminates.

OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
NG -- Continue to next step.

2. INSPECT FUSE (H-LP L LWR, H-LP R LWR)

(a) Remove the H-LP L LWR and H-LPR LWR fuses from the engine room No. 1 relay block.

(b) Measure the resistance of the fuses.

Standard resistance:

Below 1 Ohms

NG -- REPLACE FUSE
OK -- Continue to next step.

3. INSPECT HEADLIGHT RELAY (Marking: HEAD LP)





(a) Remove the headlight relay from the engine room No. 1 relay block.

(b) Measure the resistance of the headlight relay.

Standard resistance:





NG -- REPLACE HEADLIGHT RELAY
OK -- Continue to next step.

4. CHECK WIRE HARNESS (ECU - BATTERY)

(a) Disconnect the DL ECU connector.





(b) Measure the voltage of the wire harness side connector.

Standard voltage:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

5. CHECK WIRE HARNESS (HEADLIGHT - BATTERY AND BODY GROUND)

(a) Check the wire harness between the headlight (Low LH) and battery, and the headlight (Low LH) and body ground.





(1) Disconnect the B11 light connector.

(2) Turn the light control switch to the ON (HEAD) position.

(3) Measure the voltage of the wire harness side connector.

Standard voltage:





(4) Measure the resistance of the wire harness side connector.

Standard resistance:





(b) Check the wire harness between the headlight (Low RH) and battery, and the headlight (Low RH) and body ground.





(1) Disconnect the B2 light connector.

(2) Turn the light control switch to the ON (HEAD) position.

(3) Measure the voltage of the wire harness side connector.

Standard voltage:





(4) Measure the resistance of the wire harness side connector.

Standard resistance:





OK -- REPLACE HEADLIGHT ASSEMBLY

NG -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE