Headlight Relay Circuit

LIGHTING (EXT): LIGHTING SYSTEM: Headlight Relay Circuit; 2013 MY Corolla [07/2012 -]
- Headlight Relay Circuit

DESCRIPTION

* The daytime running light relay receives the light control switch HEAD signal and the ambient light level signal from the automatic light control sensor to control the headlight relay.

HINT
* If only a low beam headlight bulb on one side does not illuminate, inspect the bulb, fuse, or wire harness related to the bulb.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. INSPECT FUSE (H-LP MAIN)

(a) Remove the H-LP MAIN fuse from the engine room relay block.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

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

2. INSPECT ENGINE ROOM RELAY BLOCK

(a) Install the H-LP MAIN fuse to the engine room relay block.

(b) Remove the H-LP LH LO fuse and H-LP RH LO fuse from the engine room relay block.

NG -- INSPECT HEADLIGHT RELAY (H-LP)

OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (FUSE - BODY GROUND)

3. INSPECT HEADLIGHT RELAY (H-LP)

(a) Remove the headlight relay from the engine room relay block.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

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

4. CHECK HARNESS AND CONNECTOR (BATTERY - HEADLIGHT RELAY)

(a) Measure the voltage on the relay block side according to the value(s) in the table below.

Standard Voltage:

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

5. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY - FUSE)

(a) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

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

6. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY - DAYTIME RUNNING LIGHT RELAY)

(a) Disconnect the E91 daytime running light relay connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE Exterior Lighting System