DESCRIPTION
The main body ECU (instrument panel junction block assembly) receives a rear fog light switch information signal from the light control switch (rear fog switch), and illuminates the rear fog lights.
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 (REAR FOG LIGHT)
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 / Rear Fog Light Relay.
Check that the rear fog lights turn on/off.
| Tester Display | Test Part | Control Range | Diagnostic Note |
|---|---|---|---|
| Rear Fog Light Relay | Rear fog light | ON or OFF | - |
| OK |
|---|
| Rear fog lights turn on/off. |
| OK |
|
REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY) |
| NG |
|
INSPECT RR FOG RELAY
Remove the RR FOG relay from the No. 1 relay block.
Inspect the RR FOG relay Click here.
| NG |
|
REPLACE RR FOG RELAY |
| OK |
|
CHECK HARNESS AND CONNECTOR (REAR FOG LIGHT - BODY GROUND)
*1: for LHD
*2: for RHD
| *A | for Sedan |
| *B | for Wagon |
| *C | for LHD |
| *D | for RHD |
| *a | Front view of wire harness connector (to Rear Fog Light) |
for Sedan:
Disconnect the G58*1 or G57*2 rear fog light connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | ||||||||
|---|---|---|---|---|---|---|---|---|
| for LHD | ||||||||
|
||||||||
| for RHD | ||||||||
|
for Wagon:
Disconnect the M15*1 or M16*2 rear light connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | ||||||||
|---|---|---|---|---|---|---|---|---|
| for LHD | ||||||||
|
||||||||
| for RHD | ||||||||
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
CHECK HARNESS AND CONNECTOR (REAR FOG LIGHT RELAY - BATTERY AND TAIL RELAY)
| *a | Front view of wire harness connector (to Rear Fog Light Relay [RR FOG]) |
Remove the rear fog light relay from the 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 (REAR FOG LIGHT - REAR FOG LIGHT RELAY AND BODY GROUND)
*1: for LHD
*2: for RHD
Remove the rear fog light relay from the No. 1 relay block.
for Sedan:
Disconnect the G58*1 or G57*2 rear fog light connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| for LHD | ||||||||||||
|
||||||||||||
| for RHD | ||||||||||||
|
for Wagon:
Disconnect the M15*1 or M16*2 rear light connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| for LHD | ||||||||||||
|
||||||||||||
| for RHD | ||||||||||||
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
CHECK HARNESS AND CONNECTOR (REAR FOG LIGHT 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 |
|
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |