DESCRIPTION
The main body ECU (multiplex network body ECU) detects auto high beam switch signals. The automatic high beam system can be turned on and off by operating the automatic high beam switch.
WIRING DIAGRAM
| *a | AHBI |
| *b | Automatic High Beam Switch |
| *c | Main Body ECU (Multiplex Network Body ECU) |
CAUTION / NOTICE / HINT
Note
If the main body ECU (multiplex network body ECU) is replaced, refer to Service Bulletin.*
*: w/ Smart Entry and Start System
As the door control battery is installed between the vehicle battery and main body ECU (multiplex network body ECU), 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 (multiplex network body ECU) before performing this troubleshooting procedure.*
*: for LHD
PROCEDURE
READ VALUE USING GTS
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Enter the following menus: Body Electrical / Main Body / Data List.
Read the Data List according to the display on the GTS.
| Tester Display | Measurement Item | Range | Normal Condition | Diagnostic Note |
|---|---|---|---|---|
| Auto High Beam Main Switch | Automatic high beam switch signal | OFF or ON | OFF: Automatic high beam switch not pressed ON: Automatic high beam switch pressed |
- |
| Tester Display |
|---|
| Auto High Beam Main Switch |
| OK |
|---|
| Normal conditions listed above are displayed. |
| Result | |||
|---|---|---|---|
|
| OK |
|
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here |
| NG |
|
INSPECT AUTO HIGH BEAM SWITCH
Remove the auto high beam switch.
Inspect the auto high beam switch.
| Result | |||
|---|---|---|---|
|
| NG |
|
REPLACE AUTO HIGH BEAM SWITCH Click here |
| OK |
|
CHECK HARNESS AND CONNECTOR (AUTO HIGH BEAM SWITCH - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) AND BODY GROUND)
Disconnect the F18 main body ECU (multiplex network body ECU) connector.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |