Headlight (Hi-Beam) Circuit

LIGHTING: LIGHTING SYSTEM: Headlight (HI-BEAM) Circuit
- Headlight (HI-BEAM) Circuit

DESCRIPTION

When either of the following conditions is met, the high beam headlights come on.

* Dimmer switch in HIGH position and light control switch in HEAD position.

* Dimmer switch in HIGH position, light control switch in AUTO position, and low beam headlights are on.

HINT
* The power distributor has a fail-safe function control. If a short circuit occurs between the power distributor and high beam headlight bulb, the power distributor stops the DRL relay operation.
* The DRL relay is built into the power distributor, so unlike conventional relays, it cannot be removed for inspection.
* If only a high beam headlight on one side does not illuminate, inspect the fuse, bulb, or wire harness that is related to the bulb.
* If both right and left high beam headlights do not illuminate, read the dimmer switch HIGH signal value in the data list, and perform the DRL relay active test to determine if the malfunction exists on either the switch side or the relay side.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. PERFORM ACTIVE TEST 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 / Active Test.

(e) Check that the relay operates.

Main Body:

OK:

Relay operates. (HI-beam headlights illuminate.)

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

2. CHECK HARNESS AND CONNECTOR (SHORT IN RELAY-DRIVEN CIRCUIT)

(a) Remove the H-LP (RH) fuse from the engine room junction block assembly.

(b) Turn the light control switch to the HEAD position and turn the dimmer switch to the HIGH position.

(c) Check if the high beam headlight LH illuminates.

(d) Turn the dimmer switch to the LOW position.

(e) Install the H-LP (RH) fuse and remove the H-LP (LH) fuse.

(f) Turn the dimmer switch to the HIGH position.

(g) Check if the high beam headlight RH illuminates.

OK:

Either high beam headlight LH or RH illuminates.

OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (SHORT CIRCUIT BETWEEN FUSE AND BULB)
NG -- Continue to next step.

3. INSPECT ENGINE ROOM JUNCTION BLOCK ASSEMBLY

(a) Remove the H-LP (RH) fuse and H-LP (LH) fuse from the engine room junction block assembly.

(b) Measure the voltage between the loading slot of each fuse and body ground.

Standard voltage:

OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (OPEN CIRCUIT BETWEEN FUSE AND BODY GROUND)
NG -- Continue to next step.

4. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

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

Standard voltage:

OK -- REPLACE ENGINE ROOM JUNCTION BLOCK ASSEMBLY
NG -- Continue to next step.

5. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

(a) Disconnect the DD instrument panel junction block connector.

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

Standard voltage:

OK -- REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY
NG -- Continue to next step.

6. INSPECT ENGINE ROOM JUNCTION BLOCK ASSEMBLY

(a) Disconnect the 1D engine room junction block assembly connector.

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

Standard voltage:

OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (ENGINE ROOM J/B ASSEMBLY - INSTRUMENT PANEL J/B ASSEMBLY)
NG -- Continue to next step.

7. CHECK HARNESS AND CONNECTOR (ENGINE ROOM J/B ASSEMBLY - BATTERY AND BODY GROUND)

(a) Disconnect the 1G engine room junction block assembly connector.

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

Standard voltage:

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

Standard resistance:

OK -- REPLACE ENGINE ROOM JUNCTION BLOCK ASSEMBLY

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR