DESCRIPTION
In this circuit, the meter CPU receives auto dimmer signals from the main body ECU (driver side junction block assembly) using the CAN communication system (CAN No. 1 Bus). When the meter CPU receives an auto dimmer signal, it dims the meter illumination (warning and indicator lights). The main body ECU (driver side junction block assembly) determines whether it is daytime, twilight, or nighttime based on the waveform transmitted from the automatic light control sensor. If the main body ECU (driver side junction block assembly) determines that it is daytime, the ECU does not send an auto dimmer signal. Therefore, the meter illumination 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 is always dark, there may be a malfunction in the automatic light control sensor, main body ECU (driver side junction block assembly), CAN communication system, harness or connector, or combination meter assembly.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
HINT:
PROCEDURE
1. |
CHECK CAN COMMUNICATION SYSTEM |
(a) Check if a CAN communication DTC is output (See page
).
Result |
Proceed to |
---|---|
CAN communication DTC is not output. |
A |
CAN communication DTC is output. |
B |
B | ![]() |
GO TO CAN COMMUNICATION SYSTEM |
|
2. |
CHECK DTC (LIGHT SENSOR CIRCUIT) |
(a) Check if DTC B1244 is output (See page
).
Result |
Proceed to |
---|---|
B1244 is not output. |
A |
B1244 is output. |
B |
B | ![]() |
GO TO LIGHTING SYSTEM |
|
3. |
CHECK OPERATION (ACCESSORY METER ASSEMBLY) |
(a) Turn the ignition switch to ON.
(b) Turn the light control switch to the tail, head, or AUTO position.
(c) Cover the automatic light control sensor.
(d) Check the accessory meter assembly illumination.
Result |
Proceed to |
---|---|
Accessory meter assembly illumination does not operate normally. |
A |
Accessory meter assembly illumination operates normally. |
B |
HINT:
The accessory meter assembly illumination dims according to the dimmer signal as the combination meter assembly does. Therefore, when only the meter illumination is always dark, there may be a malfunction in the combination meter assembly.
B | ![]() |
REPLACE COMBINATION METER ASSEMBLY |
|
4. |
CHECK OPERATION (AUTOMATIC LIGHT CONTROL SYSTEM) |
(a) Turn the ignition switch to ON.
(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 low beam headlights and taillights go off.
Result |
Proceed to |
---|---|
Automatic light control system operates normally. |
A |
Automatic light control system does not operate normally. |
B |
B | ![]() |
CHECK LIGHTING SETTING |
|
5. |
REPLACE MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK ASSEMBLY) |
(a) Replace the main body ECU (driver side junction block assembly) with a new
or a normal one (See page ).
OK:
The operation of the combination meter assembly returns to normal.
HINT:
The meter CPU controls the meter illumination based on an auto dimmer signal from the main body ECU (driver side junction block assembly). When the meter illumination is always dark (very dim), it may be due to the main body ECU (driver side junction block assembly) sending an auto dimmer signal to the meter CPU because of a malfunction in the main body ECU (driver side junction block assembly).
OK | ![]() |
END |
NG | ![]() |
REPLACE COMBINATION METER ASSEMBLY |
Lost Communication with ECM / PCM "A" (U0100,U0129)
DESCRIPTION
The combination meter assembly communicates with the ECM via the CAN communication
system (CAN No. 1 Bus).
DTC No.
DTC Detection Condition
Trouble Area
U0100
When either of the follow ...
Speed Signal Malfunction (B15C2)
DESCRIPTION
The navigation receiver assembly receives a vehicle speed signal from the combination
meter assembly and information from the navigation antenna assembly, and then adjusts
the vehicle position.
The navigation receiver assembly stores this DTC ...
Parking Brake System
Problem Symptoms Table
PROBLEM SYMPTOMS TABLE
HINT:
Use the table below to help determine the cause of problem symptoms. If multiple
suspected areas are listed, the potential causes of the symptoms are listed in order
of probability in the "Suspe ...