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 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 upwards cancels the above dimmer control.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. SYSTEM CHECK
(a) Ignition switch on (IG).
(b) Turn the light control rheostat knob fully upwards.
(c) Turn the light control rheostat knob fully downwards.
(d) Turn the light control rheostat knob fully upwards and light control switch is on Tail or HEAD.
(e) Check the meter illumination.
Result:






B -- READ VALUE USING TECHSTREAM (TAIL CANCEL SW)
A -- Continue to next step.
2. READ VALUE USING TECHSTREAM (RHEOSTAT)
(a) Connect Techstream to the DLC3.
(b) Ignition 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 -- CHECK HARNESS AND CONNECTOR (COMBINATION METER - LIGHT CONTROL RHEOSTAT)
OK -- Continue to next step.
3. READ VALUE USING TECHSTREAM (TAIL CANCEL SW)
(a) Connect Techstream to the DLC3.
(b) Ignition 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 -- CHECK HARNESS AND CONNECTOR (COMBINATION METER - LIGHT CONTROL RHEOSTAT)
OK -- REPLACE COMBINATION METER ASSEMBLY
4. CHECK HARNESS AND CONNECTOR (COMBINATION METER - LIGHT CONTROL RHEOSTAT)





(a) Disconnect the E1 and D4 connectors.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
5. 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 -- REPLACE COMBINATION METER ASSEMBLY
6. CHECK HARNESS AND CONNECTOR (COMBINATION METER - LIGHT CONTROL RHEOSTAT)





(a) Disconnect the E1 and D4 connectors.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
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 -- REPLACE COMBINATION METER ASSEMBLY