DESCRIPTION
for Halogen Headlight:
The main body ECU (multiplex network body ECU) controls the high beam headlights via the engine room junction block assembly.
for LED Headlight:
The main body ECU (multiplex network body ECU) controls the high beam headlights via the DIMMER relay.
WIRING DIAGRAM
for LED Headlight:
for Halogen Headlight:
INSPECTION PROCEDURE
Note
Inspect the fuses and lights for circuits related to this system before performing the following inspection procedure.
PROCEDURE
PERFORM ACTIVE TEST USING TECHSTREAM
Connect the Techstream to the DLC3.
Turn the ignition switch to ON.
Turn the Techstream on.
Enter the following menus: Body Electrical / Main Body / Active Test.
Perform the Active Test according to the display on the Techstream.
| Tester Display | Test Part | Control Range | Diagnostic Note |
|---|---|---|---|
| Head Light Hi | High beam headlights | ON/OFF | - |
| OK |
|---|
| High beam headlights illuminate. |
| Result | ||||||||
|---|---|---|---|---|---|---|---|---|
|
| B |
|
INSPECT ENGINE ROOM JUNCTION BLOCK ASSEMBLY Click here |
| C |
|
INSPECT DIMMER RELAY Click here |
| A |
|
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here
INSPECT ENGINE ROOM JUNCTION BLOCK ASSEMBLY
Using a voltmeter, check the signal reading of the engine room junction block assembly Click here.
| OK |
|---|
| Output signal reading is normal. |
| NG |
|
INSPECT ENGINE ROOM JUNCTION BLOCK ASSEMBLY (RESULTS OF SIGNAL READING CHECK) Click here |
| OK |
|
CHECK HARNESS AND CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY POWER SOURCE AND BODY GROUND)
Remove the engine room junction block assembly from the engine room relay block and junction block assembly Click here.
| *a | Component without engine room junction block assembly (Engine Room Relay Block and Junction Block Assembly) |
- | - |
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
CHECK HARNESS AND CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY
Disconnect the 3D instrument panel junction block assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY
| *a | Component without harness connected (Instrument Panel Junction Block Assembly) |
Remove the instrument panel junction block assembly Click here.
Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
| NG |
|
REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here |
| OK |
|
REPLACE ENGINE ROOM JUNCTION BLOCK ASSEMBLY
Replace the engine room junction block assembly with a new or known good one Click here.
Check that the high beam headlights operate normally.
| OK |
|---|
| High beam headlights operate normally. |
| NG |
|
REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here |
| OK |
|
END (ENGINE ROOM JUNCTION BLOCK ASSEMBLY WAS DEFECTIVE)
INSPECT DIMMER RELAY
| *a | Component without harness connected (DIMMER Relay) |
Remove the DIMMER relay from the No. 2 engine room relay block and junction block assembly.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
| NG |
|
REPLACE DIMMER RELAY |
| OK |
|
CHECK HARNESS AND CONNECTOR (H-LP HI MAIN FUSE - DIMMER RELAY)
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)
Disconnect the A86 headlight assembly LH connector.
Disconnect the A89 headlight assembly RH connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
CHECK HARNESS AND CONNECTOR (DIMMER RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)
Disconnect the 3D instrument panel junction block assembly connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | |||||||||
|---|---|---|---|---|---|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY
| *a | Component without harness connected (Instrument Panel Junction Block Assembly) |
Remove the instrument panel junction block assembly Click here.
Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
| NG |
|
REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here |
| OK |
|
REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here