DESCRIPTION
The main body ECU (multiplex network body ECU) controls the daytime running lights (parking lights) via the engine room junction block assembly.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
Note
If the main body ECU (multiplex network body ECU) is replaced, refer to Service Bulletin.
PROCEDURE
CHECK OPERATION (CLEARANCE LIGHTS)
Check the operation of the clearance lights.
| OK |
|---|
| The clearance lights operate normally. |
| NG |
|
GO TO PROBLEM SYMPTOMS TABLE Click here |
| OK |
|
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.
Perform the Active Test according to the display on the GTS.
| Tester Display | Test Part | Control Range | Diagnostic Note |
|---|---|---|---|
| Daytime Running Light | Daytime running lights | ON/OFF | - |
| OK |
|---|
| The daytime running lights illuminate. |
| OK |
|
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here |
| NG |
|
CHECK 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 connected (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 main body ECU (multiplex network body ECU) 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 |
|
CHECK HARNESS AND CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY - HEADLIGHT ASSEMBLY)
Disconnect the A70 headlight assembly LH connector.
Disconnect the A75 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 ENGINE ROOM JUNCTION BLOCK ASSEMBLY
Replace the engine room junction block assembly with a new or known good one Click here.
Check that the daytime running lights operate normally.
| OK |
|---|
| The daytime running lights operate normally. |
| OK |
|
END (ENGINE ROOM JUNCTION BLOCK ASSEMBLY WAS DEFECTIVE) |
| NG |
|
REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here |