DESCRIPTION
The main body ECU receives light control switch and dimmer switch information signals from the headlight dimmer switch, and illuminates the high beam headlight.
WIRING DIAGRAM
INSPECTION PROCEDURE
Tech Tips
Inspect the fuses and bulbs for circuits related to this system before performing the following inspection procedure.
PROCEDURE
PERFORM ACTIVE TEST USING INTELLIGENT TESTER (HEADLIGHT [HIGH])
Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON.
Turn the intelligent tester on.
Enter the following menus: Body / Main Body / Active Test / Head Light Hi.
Check that the headlight (high) turns on/off.
| Tester Display | Test Part | Control Range | Diagnostic Note |
|---|---|---|---|
| Head Light Hi | Headlight (High) | ON or OFF | - |
Tech Tips
Perform the inspection with the low beam headlights turned on. (for HID Headlight)
| OK |
|---|
| Headlight (high) turns on/off. |
| NG |
|
CHECK HARNESS AND CONNECTOR (HEADLIGHT [HIGH] - HEADLIGHT DIMMER RELAY) Click here |
| OK |
|
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here
CHECK HARNESS AND CONNECTOR (HEADLIGHT [HIGH] - HEADLIGHT DIMMER RELAY)
| *1 | Front view of wire harness connector (to Headlight [High]) |
| *2 | for LH |
| *3 | for RH |
| *4 | for HID Headlight |
| *5 | for Halogen Headlight |
for HID Headlight:
Disconnect the A58 or A57 headlight (high) connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | ||||||||
|---|---|---|---|---|---|---|---|---|
| for LH | ||||||||
|
||||||||
| for RH | ||||||||
|
for Halogen Headlight:
Disconnect the A58 or A57 headlight (high) connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | ||||||||
|---|---|---|---|---|---|---|---|---|
| for LH | ||||||||
|
||||||||
| for RH | ||||||||
|
| NG |
|
INSPECT HEADLIGHT DIMMER RELAY (DIMMER) Click here |
| OK |
|
CHECK HARNESS AND CONNECTOR (HEADLIGHT [HIGH] - BODY GROUND)
| *1 | Front view of wire harness connector (to Headlight [High]) |
| *2 | for LH |
| *3 | for RH |
| *4 | for HID Headlight |
| *5 | for Halogen Headlight |
for HID Headlight:
Disconnect the A58 or A57 headlight (high) connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
| for LH | ||||||
|
||||||
| for RH | ||||||
|
for Halogen Headlight:
Disconnect the A58 or A57 headlight (high) connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
| for LH | ||||||
|
||||||
| for RH | ||||||
|
| Result | Proceed to |
|---|---|
| OK (for HID Headlight) | A |
| OK (for Halogen Headlight) | B |
| NG | C |
| B |
|
REPLACE HEADLIGHT ASSEMBLY Click here |
| C |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| A |
|
REPLACE HEADLIGHT ASSEMBLY Click here
INSPECT HEADLIGHT DIMMER RELAY (DIMMER)
| *1 | for HID Headlight: |
| *2 | for Halogen Headlight: |
Remove the headlight dimmer relay from the engine room No. 1 relay block.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||||
|---|---|---|---|---|---|---|---|---|
|
| NG |
|
REPLACE HEADLIGHT DIMMER RELAY |
| OK |
|
CHECK HARNESS AND CONNECTOR (HEADLIGHT DIMMER RELAY - BATTERY)
| *1 | Component without relay connected (Engine Room No. 1 Relay Block) |
| *2 | Headlight Dimmer Relay (DIMMER [for HID Headlight]) |
| *3 | Headlight Dimmer Relay (DIMMER [for Halogen Headlight]) |
Remove the headlight dimmer relay from the engine room No. 1 relay block.
for HID Headlight:
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
for Halogen Headlight:
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
CHECK HARNESS AND CONNECTOR (HEADLIGHT DIMMER RELAY - HEADLIGHT [HIGH])
| *1 | Component without relay connected (Engine Room No. 1 Relay Block [for HID Headlight]) |
| *2 | Component without relay connected (Engine Room No. 1 Relay Block [for Halogen Headlight]) |
| *3 | Front view of wire harness connector (to Headlight [High]) |
| *4 | for LH |
| *5 | for RH |
| *6 | for HID Headlight |
| *7 | for Halogen Headlight |
Remove the headlight dimmer relay from the engine room No. 1 relay block.
for HID Headlight:
Disconnect the A58 or A57 headlight (high) connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| for LH | |||||||||
|
|||||||||
| for RH | |||||||||
|
for Halogen Headlight:
Disconnect the A58 or A57 headlight (high) connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| for LH | |||||||||
|
|||||||||
| for RH | |||||||||
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
CHECK HARNESS AND CONNECTOR (HEADLIGHT DIMMER RELAY - MAIN BODY ECU)
| *1 | Front view of wire harness connector (to Main Body ECU) |
Disconnect the D80 main body ECU connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | ||||||
|---|---|---|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)