Meter Illumination Is Always Dark

METER: METER / GAUGE SYSTEM: Meter Illumination is Always Dark
- Meter Illumination is Always Dark

DESCRIPTION

In this circuit, the meter CPU receives auto dimmer signals from the main body ECU using the CAN communication lines (CAN MS Bus). When the meter CPU receives an auto dimmer signal, it dims the meter illumination. The main body ECU determines whether it is daytime, twilight, or nighttime based on the waveform transmitted from the automatic light control sensor. If the main body ECU determines that it is daytime, the ECU does not send auto dimmer signals. Therefore, the meter illumination (warning and indicator lights) will not dim even if the driver accidentally turns the light control switch to the TAIL or HEAD position in daytime.

HINT
When the meter illumination is always dark, or the meter illumination does not dim at night, there may be a malfunction in automatic light control sensor, main body ECU, CAN communication system, wire harness or connector, or combination meter assembly.

WIRING DIAGRAM

1. for Manual A/C:





2. for Automatic A/C:





INSPECTION PROCEDURE

PROCEDURE

1. CHECK CAN COMMUNICATION SYSTEM

(a) Check if CAN communication DTC is output .

Result:





B -- GO TO CAN COMMUNICATION SYSTEM
A -- Continue to next step.

2. CHECK DTC

(a) Check if DTC B1244 is output Reading and Clearing Diagnostic Trouble Codes.

Result:





B -- GO TO LIGHTING SYSTEM B1244
A -- Continue to next step.

3. READ VALUE USING TECHSTREAM

(a) Connect Techstream to the DLC3.

(b) Ignition switch on (IG).

(c) Turn the tester on.

(d) Turn the light control rheostat to the TAIL/HEAD position.

(e) Enter the following menus: Body Electrical / Main Body / Data List.

(f) Check the meter illumination.

Main Body:





OK:

Normal condition listed above is displayed.

HINT
Meter illumination is adjusted by automatic light control system and controlled according to the outside light. The automatic light control sensor sensitiveness can be customized. Therefore, when the Data List value is normal, confirm the sensitivity setting in the customization table of the automatic light control system.

NG -- REPLACE COMBINATION METER ASSEMBLY

OK -- CHECK LIGHTING SETTING Programming and Relearning

4. REPLACE COMBINATION METER ASSEMBLY

(a) Replace the combination meter assembly with a new or a normal one Removal.

OK:

The operation of the combination meter assembly returns to normal.

NG -- REPLACE MAIN BODY ECU

OK -- END