Operating Light Control Rheostat Does Not Change Light Brightness

METER: METER / GAUGE SYSTEM: Operating Light Control Rheostat does not Change Light Brightness
- Operating Light Control Rheostat does not Change Light Brightness

DESCRIPTION

* The meter CPU receives signals for adjusting illumination on the meter and instrument panel from this circuit

* The meter CPU detects the illumination level selected by the user according to the position of the rheostat knob.

HINT
* This model is equipped with an Optitron meter, therefore the meter illuminates even in the daytime.
* The meter illumination level can be adjusted by turning the rheostat.
* The meter illumination dims when the light control switch is turned to the TAIL or HEAD position at night.
* Turning the rheostat knob fully clockwise cancels the above dimmer control.
* During light control switch TAIL/HEAD position, turn the rheostat knob fully counterclockwise, then the meter illumination turns off.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. SYSTEM CHECK

Result:





B -- INSPECT LIGHT CONTROL RHEOSTAT
A -- Continue to next step.

2. READ VALUE USING TECHSTREAM (RHEOSTAT VALUE)

(a) Connect Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the tester ON.

(d) Enter the following menus: Body Electrical / Combination Meter / Active Test.

(e) Check the values by referring to the table below.

Combination Meter:





OK:

The value displayed on the tester gradually changes as the actual rheostat operation.

NG -- INSPECT LIGHT CONTROL RHEOSTAT
OK -- Continue to next step.

3. READ VALUE USING TECHSTREAM (TAIL CANCEL SW)

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the tester ON.

(d) Enter the following menus: Body Electrical / Combination Meter / Data List.

(e) Check the values by referring to the table below.

Combination Meter:





OK:

Condition displayed on the tester is the same as the actual rheostat position.

NG -- INSPECT LIGHT CONTROL RHEOSTAT

OK -- REPLACE COMBINATION METER ASSEMBLY

4. INSPECT LIGHT CONTROL RHEOSTAT

(a) Remove the light control rheostat with the connector still connected.





(b) Measure the resistance according to the value(s) in the table below.

Standard resistance:





NG -- REPLACE LIGHT CONTROL RHEOSTAT
OK -- Continue to next step.

5. CHECK HARNESS AND CONNECTOR (COMBINATION METER - LIGHT CONTROL RHEOSTAT)

(a) Disconnect the J34 and J15 connectors.





(b) Measure the resistance according to the value(s) in the table below.

Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE COMBINATION METER ASSEMBLY

6. READ VALUE USING TECHSTREAM (TAIL CANCEL SW)

(a) Connect Techstream to the DLC3.

(b) Engine switch on (IG).

(c) Turn the tester ON.

(d) Enter the following menus: Body Electrical / Combination Meter / Data List.

(e) Check the values by referring to the table below.

Combination Meter:





OK:

Rheostat position displayed on the tester is same as the actual rheostat position.

NG -- INSPECT LIGHT CONTROL RHEOSTAT

OK -- REPLACE COMBINATION METER ASSEMBLY

7. INSPECT LIGHT CONTROL RHEOSTAT

(a) Remove the light control rheostat with connector still connected.





(b) Measure the resistance according to the value(s) in the table below.

Standard resistance:





NG -- REPLACE LIGHT CONTROL RHEOSTAT
OK -- Continue to next step.

8. CHECK HARNESS AND CONNECTOR (COMBINATION METER - LIGHT CONTROL RHEOSTAT)

(a) Disconnect the J34 and J15 connectors.





(b) Measure the resistance according to the value(s) in the table below.

Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE COMBINATION METER ASSEMBLY