DESCRIPTION
The main body ECU (instrument panel junction block assembly) receives light control switch and dimmer switch information signals from the headlight dimmer switch, and illuminates the high beam headlight.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
Note
As the door control battery is installed between the vehicle battery and main body ECU (instrument panel junction block assembly), first perform the inspections in On-Vehicle Inspection to confirm that there are no malfunctions in the power source circuit for the main body ECU (instrument panel junction block assembly) before performing this troubleshooting 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 GTS (HEAD LIGHT HI)
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Body Electrical / 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.
OK |
---|
Headlight (high) turns on/off. |
OK |
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here |
NG |
CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY [HIGH] - HEADLIGHT DIMMER RELAY)
*1: for LH
*2: for RH
for LED Headlight:
*A | for LH |
*B | for RH |
*a | Front view of wire harness connector (to Headlight Assembly [High]) |
Disconnect the A77*1 or A76*2 headlight assembly (high) connector.
Measure the voltage according to the value(s) in the table below.
Standard Voltage | ||||||||
---|---|---|---|---|---|---|---|---|
for LH | ||||||||
|
||||||||
for RH | ||||||||
|
for Halogen Headlight:
*A | for LH |
*B | for RH |
*a | Front view of wire harness connector (to Headlight Assembly [High]) |
Disconnect the A71*1 or A70*2 headlight assembly (high) connector.
Measure the voltage according to the value(s) in the table below.
Standard Voltage | ||||||||
---|---|---|---|---|---|---|---|---|
for LH | ||||||||
|
||||||||
for RH | ||||||||
|
NG |
INSPECT DIMMER RELAY Click here |
OK |
CHECK HARNESS AND CONNECTOR (HEADLIGHT [HIGH] - BODY GROUND)
*1: for LH
*2: for RH
for LED Headlight:
*A | for LH |
*B | for RH |
*a | Front view of wire harness connector (to Headlight Assembly [High]) |
Disconnect the A77*1 or A76*2 headlight (high) connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||
---|---|---|---|---|---|---|
for LH | ||||||
|
||||||
for RH | ||||||
|
for Halogen Headlight:
*A | for LH |
*B | for RH |
*a | Front view of wire harness connector (to Headlight Assembly [High]) |
Disconnect the A71*1 or A70*2 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 LED Headlight) | A |
OK (for Halogen Headlight) | B |
NG | C |
A |
REPLACE HEADLIGHT ASSEMBLY Click here |
B |
REPLACE HEADLIGHT ASSEMBLY Click here |
C |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
INSPECT DIMMER RELAY
Remove the 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 DIMMER RELAY |
OK |
CHECK HARNESS AND CONNECTOR (DIMMER RELAY - BATTERY)
*a | Front view of wire harness connector (to DIMMER Relay) |
Remove the DIMMER relay from the engine room No. 1 relay block.
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 (DIMMER RELAY - HEADLIGHT ASSEMBLY [HIGH])
*1: for LH
*2: for RH
Remove the DIMMER relay from the engine room No. 1 relay block.
for LED Headlight:
Disconnect the A77*1 or A76*2 headlight assembly (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 A71*1 or A70*2 headlight assembly (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 [INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY])
*a | Front view of wire harness connector (to Main Body ECU [Instrument Panel Junction Block Assembly]) |
Disconnect the main body ECU (instrument panel junction block assembly) connector.
Measure the voltage according to the value(s) in the table below.
Standard Voltage | ||||||
---|---|---|---|---|---|---|
|
OK |
REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY) |
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |