Meter Illumination Is Always Dark
METER: METER / GAUGE SYSTEM: Meter Illumination is Always Dark
Meter Illumination is Always Dark
DESCRIPTION
In this circuit, the NO. 1 meter ECU receives auto dimmer signals from the main body ECU using the CAN communication lines. When the NO. 1 meter ECU receives an auto dimmer signal, it dims the meter 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 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.
HINT: When the meter illumination does not dim at night, the light control rheostat position is at the tail cancel position, or there may be a malfunction in the automatic light control sensor, main body ECU, CAN communication system, wire harness or connector, or combination meter.
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
1. CHECK CAN COMMUNICATION SYSTEM
(a) Check for the DTC Reading and Clearing Diagnostic Trouble Codes.
Result:
C -- Go to LIGHTING SYSTEM
B -- Go to CAN COMMUNICATION SYSTEM
A -- Continue to next step.
2. PERFORM ACTIVE TEST USING INTELLIGENT TESTER OR TECHSTREAM (DIMMER SWITCH)
(a) Operate the intelligent tester or Techstream according to the display and select "ACTIVE TEST" or "Active Test".
(1) Intelligent tester
MAIN BODY:
(2) Techstream
Main Body:
OK:
Meter illumination is dimmed when the dimmer switch is ON.
HINT: Refer to the sensitivity setting in the customization table of the automatic light control system Programming and Relearning.
NG -- REPLACE NO. 1 METER ECU
OK -- CHECK LIGHTING SETTING
3. REPLACE NO. 1 METER ECU
(a) Temporarily replace the combination meter with a new one Disassembly.
NEXT -- Continue to next step.
4. CHECK NO. 1 METER ECU
(a) Check that the operation of the combination meter returns to normal Component Tests and General Diagnostics.
OK:
Operation of combination meter returns to normal.
NG -- REPLACE MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK)
OK -- END (COMBINATION METER IS DEFECTIVE)