Meter Illumination does not Dim at Night

DESCRIPTION

1. In this circuit, the meter CPU receives auto dimmer signals from the main body ECU RH using the BEAN lines.
   
2. When the meter CPU receives an auto dimmer signal, it dims the meter illumination.
   
3. The main body ECU RH determines whether it is daytime, twilight, or nighttime based on the waveform transmitted from the automatic light control sensor.
   
4. If the main body ECU RH determines that it is daytime, the ECU does not send auto dimmer signals.
   
5. 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.
   

WIRING DIAGRAM

INSPECTION PROCEDURE

1. CHECK DTC

1. Check if DTC B1244 is output (Click here).
   

   Result:

   Result	Proceed to
   B1244 is not output	A
   B1244 is output	B

B	GO TO LIGHTING SYSTEM

A

2. PERFORM ACTIVE TEST BY INTELLIGENT TESTER

1. Connect the intelligent tester to the DLC3.

2. Engine switch on (IG).

3. Turn the tester ON.

4. Enter the following menus: Diagnosis / Body / Integrated J/B / Active Test.

5. Check the meter illumination.

Integrated J/B: 

Item	Test Details	Diagnostic Note
Dimmer Signal	Auto dimmer signal ON/OFF	-

OK:

The meter illumination is dimmed when the DIMMER SIG is ON.

HINT:

Refer to the sensitivity setting in the customization table of the automatic light control system. (Click here)

NG	Go to step 3

OK
CHECK LIGHTING SETTING

3. REPLACE COMBINATION METER ASSEMBLY

OK:

The operation of the combination meter assembly returns to normal.

NG	REPLACE MAIN BODY ECU RH

OK
END