DESCRIPTION
The main body ECU (multiplex network body ECU) controls the low beam headlights.
WIRING DIAGRAM
for HID Headlight
for Halogen Headlight
CAUTION / NOTICE / HINT
Note
Inspect the fuses and bulbs for circuits related to this system before performing the following procedure.
PROCEDURE
PERFORM ACTIVE TEST USING GTS
Connect the GTS to the DLC3.
Turn the power switch on (IG).
Turn the GTS on.
Enter the following menus: Body Electrical / Main Body / Active Test.
Check that the relay operates.
Tester Display | Measurement Item | Control Range | Diagnostic Note |
---|---|---|---|
Headlight Relay | Headlight relay (Low beam headlights) | ON/OFF | - |
Tester Display |
---|
Headlight Relay |
OK |
---|
Headlight relay operates. (Low beam headlights illuminate.) |
Result | |||
---|---|---|---|
|
OK |
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here |
NG |
INSPECT H-LP RELAY
Remove the H-LP relay from the engine room relay block and junction block assembly.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||||
---|---|---|---|---|---|---|---|---|---|
|
Result | |||
---|---|---|---|
|
NG |
REPLACE H-LP RELAY |
OK |
CHECK HARNESS AND CONNECTOR (H-LP-MAIN FUSE - H-LP RELAY)
Measure the voltage according to the value(s) in the table below.
Standard Voltage | |||||||||
---|---|---|---|---|---|---|---|---|---|
|
Result | |||
---|---|---|---|
|
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
OK |
CHECK HARNESS AND CONNECTOR (H-LP RELAY - HEADLIGHT ASSEMBLY LH AND HEADLIGHT ASSEMBLY RH)
for HID Headlight:
Disconnect the A78 headlight assembly LH connector.
Disconnect the A76 headlight assembly RH connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
|
for Halogen Headlight:
Disconnect the A70 headlight assembly LH connector.
Disconnect the A73 headlight assembly RH connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
|
Result | |||
---|---|---|---|
|
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
OK |
CHECK HARNESS AND CONNECTOR (H-LP RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)
Disconnect the 3A instrument panel junction block assembly connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance | |||||||||
---|---|---|---|---|---|---|---|---|---|
|
Result | |||
---|---|---|---|
|
NG |
REPAIR OR REPLACE HARNESS OR CONNECTOR |
OK |
INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY
Remove the instrument panel junction block assembly.
for LHD: Click here
for RHD: 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.
*a | Component without harness connected (Instrument Panel Junction Block Assembly) |
- | - |
Standard Resistance | |||||||||
---|---|---|---|---|---|---|---|---|---|
|
Result | |||
---|---|---|---|
|
OK |
REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) for LHD: Click here |
NG |
REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY for LHD: Click here |