DESCRIPTION
The main body ECU (multiplex network body ECU) receives headlight dimmer switch information signals, and illuminates the high beam headlight.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
Tech Tips
Inspect the fuses and bulbs for circuits related to this system before performing the following inspection procedure.
Note
Initialization is necessary when the main body ECU (multiplex network body ECU) is replaced Click here.*
*: w/ Automatic Light Control System
PROCEDURE
PERFORM ACTIVE TEST USING INTELLIGENT TESTER (HEAD LIGHT HI)
Using the intelligent tester, perform the Active Test Click here.
| Tester Display | Test Part | Control Range | Diagnostic Note |
|---|---|---|---|
| Head Light Hi | Headlight dimmer relay | ON/OFF | - |
| OK |
|---|
| Relay operates (high beam headlights illuminate). |
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here |
| A |
|
INSPECT HEADLIGHT DIMMER RELAY (DIM)
Remove the headlight dimmer relay from the No. 2 engine room relay block.
Inspect the headlight dimmer relay Click here.
| NG |
|
REPLACE HEADLIGHT DIMMER RELAY |
| OK |
|
CHECK HARNESS AND CONNECTOR (BATTERY - DIMMER RELAY)
| *a | No. 2 Engine Room Relay Block (DIM Relay Terminal) |
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 - INSTRUMENT PANEL JUNCTION BLOCK)
Disconnect the 3C instrument panel junction block assembly connector.
Measure the resistance according to the value(s) in the table below.
| *a | No. 2 Engine Room Relay Block (DIM Relay Terminal) |
*b | Front view of wire harness connector (to Instrument Panel Junction Block Assembly) |
| Standard Resistance (Check for Open) | ||||||
|---|---|---|---|---|---|---|
|
| Standard Resistance (Check for Short) | ||||||
|---|---|---|---|---|---|---|
|
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
INSPECT 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.
| *a | Component without harness connected (Instrument Panel Junction Block Assembly) |
- | - |
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
| OK |
|
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here |
| NG |
|
REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here |