Meter Illumination Is Always Dark

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

DESCRIPTION

This inspection is only for vehicles with automatic light control.

The meter CPU receives signals from this circuit to adjust the illumination of the meter, instrument panel and accessory meter assembly. The meter CPU sets the illumination level based on the user operation of the light control rheostat.

HINT
* The meter illumination level can be adjusted by rotating the light control rheostat dial up and down.
* The meter illumination dims when the light control switch is turned to the tail or head position at night.
* Setting the meter illumination to maximum brightness cancels the above dimming of the meter illumination.

WIRING DIAGRAM





INSPECTION PROCEDURE

HINT
Setting the meter illumination to minimum brightness turns off the meter illumination when the light control switch is changed to the tail or head position, or changed to the AUTO position at night.

PROCEDURE

1. CHECK CAN COMMUNICATION SYSTEM

(a) Check if a CAN communication DTC is output Diagnosis System.

Result





B -- GO TO CAN COMMUNICATION SYSTEM How to Proceed With Troubleshooting
A -- Continue to next step.

2. CHECK DTC (LIGHT SENSOR CIRCUIT)

(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. CHECK OPERATION (HEATER CONTROL PANEL)

(a) Turn the ignition switch to ON.

(b) Turn the light control switch to the tail, head or AUTO position.

(c) Cover the automatic light control sensor.

(d) Check the heater control panel illumination.

Result





HINT
Both the heater control panel and combination meter assembly illumination dim according to the dimmer signal. Therefore, when only the meter illumination is always dark, there may be a malfunction in the combination meter assembly.

B -- REPLACE COMBINATION METER ASSEMBLY Removal
A -- Continue to next step.

4. CHECK OPERATION (AUTOMATIC LIGHT CONTROL SYSTEM)

(a) Turn the ignition switch to ON.

(b) Turn the light control switch to the AUTO position.

(c) Cover the automatic light control sensor.

(d) Check the taillights and low beam headlights.

OK:

The taillights and low beam headlights come on.

(e) Uncover the automatic light control sensor.

(f) Check the low beam headlights and taillights.

OK:

The taillights and low beam headlights go off.

Result





B -- GO TO LIGHTING SETTING Interior Lighting System
A -- Continue to next step.

5. REPLACE MAIN BODY ECU

(a) Replace the main body ECU with a new or normally functioning one Removal.

OK:

The operation of the combination meter assembly returns to normal.

HINT
The meter CPU controls the meter illumination based on an auto dimmer signal from the main body ECU. When the meter illumination is always dark (very dim), it may be due to the main body ECU sending an auto dimmer signal to the meter CPU because of a malfunction in the main body ECU.

NG -- REPLACE COMBINATION METER ASSEMBLY Removal

OK -- END