METER / GAUGE SYSTEM - Meter Illumination is Always Dark

DESCRIPTION

In this circuit, the meter CPU receives auto dimmer signals from the main body ECU RH using the BEAN lines.

When the meter CPU receives an auto dimmer signal, it dims the meter illumination.

The main body ECU RH determines whether it is daytime, twilight, or nighttime based on the waveform transmitted from the automatic light control sensor.

If the main body ECU RH 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.

WIRING DIAGRAM

Meter / Gauge System - Meter Illumination Is Always Dark. METER. Lexus IS250 IS220d GSE20 ALE20

INSPECTION PROCEDURE

1.CHECK DTC

Check if DTC B1244 is output .

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

Go to step 3

CHECK LIGHTING SETTING

3.REPLACE COMBINATION METER ASSEMBLY

OK:
The operation of the combination meter assembly returns to normal.

REPLACE MAIN BODY ECU RH

END