Illumination Circuit: Description

The clock assembly uses this circuit to receive the auto dimmer signal and tail cancel signal. When the clock assembly receives an auto dimmer signal from the main body ECU through the combination meter assembly via the direct line, the combination meter assembly causes the clock display to be dimmed. When the meter CPU receives an auto dimmer signal, it dims the meter illumination and clock 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 clock illumination (multi-information display) will not dim even if the driver accidentally turns the light control switch to the TAIL or HEAD position in daytime.

HINT: 

If the automatic light control sensor has a malfunction, DTC B1244 is output. Refer to DTC B1244: Light Sensor Circuit Malfunction