Meter Illumination Is Always Dark

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

DESCRIPTION

The meter ECU receives signals from this circuit to adjust the illumination of the meter and instrument panel. The meter ECU sets the illumination level based on the user operation of the light control rheostat up or down switches.

HINT
* The meter illumination level can be adjusted by pressing the light control rheostat up or down switches.
* 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
The meter illumination can be customized by pressing the light control rheostat up or down switch.

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 power switch on (IG).

(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 the 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 power switch on (IG).

(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 -- CHECK LIGHTING SETTING Customize Parameters
A -- Continue to next step.

5. REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

(a) Replace the main body ECU (multiplex network body ECU) with a new or a known good one Removal.

OK:

The operation of the combination meter assembly returns to normal.

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

NG -- REPLACE COMBINATION METER ASSEMBLY Removal

OK -- END