Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM100000000VJOH
Model Year Start: 2016 Model: Sienna Prod Date Range: [12/2015 -           ]
Title: METER / GAUGE / DISPLAY: METER / GAUGE SYSTEM: Meter Illumination does not Dim at Night; 2016 - 2020 MY Sienna [12/2015 -        ]

Meter Illumination does not Dim at Night

DESCRIPTION

In this circuit, the meter CPU receives auto dimmer signals from the main body ECU using the CAN communication system (CAN V1 Bus). When the meter CPU receives an auto dimmer signal, it dims the meter illumination (warning and indicator lights). The main body ECU (multiplex network 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 (multiplex network body ECU) determines that it is nighttime and the light control switch is in the tail, head, or AUTO, the ECU sends an auto dimmer signal. According to the signal, the combination meter assembly dims the meter illumination.

HINT:

When the meter illumination does not dim at night, there may be a malfunction in the automatic light control sensor, main body ECU (multiplex network body ECU), CAN communication system, harness or connector, or combination meter assembly.

WIRING DIAGRAM

  • Refer to Meter Illumination is Always Dark (See page 2016 - 2020 MY Sienna [12/2015 -        ]; METER / GAUGE / DISPLAY: METER / GAUGE SYSTEM: Meter Illumination is Always Dark+ ).

CAUTION / NOTICE / HINT

HINT:

  • The automatic light control sensor sensitiveness can be customized (See page 2016 - 2017 MY Sienna [12/2015 - 11/2017]; LIGHTING (EXT): LIGHTING SYSTEM: CUSTOMIZE PARAMETERS 2018 - 2020 MY Sienna [11/2017 -        ]; LIGHTING (EXT): LIGHTING SYSTEM: CUSTOMIZE PARAMETERS ).
  • Setting the meter illumination to maximum brightness prevents the meter illumination from dimming when the light control switch is changed to the tail, head or AUTO position at night. Therefore, check the meter illumination setting before proceeding to the following steps.

PROCEDURE

1.

CHECK CAN COMMUNICATION SYSTEM

(a) Check if a CAN communication DTC is output (See page 2016 MY Sienna [12/2015 - 08/2016]; NETWORKING: CAN COMMUNICATION SYSTEM: DIAGNOSIS SYSTEM 2017 MY Sienna [08/2016 - 11/2017]; NETWORKING: CAN COMMUNICATION SYSTEM: DIAGNOSIS SYSTEM 2018 MY Sienna [11/2017 - 08/2018]; NETWORKING: CAN COMMUNICATION SYSTEM: DIAGNOSIS SYSTEM 2019 - 2020 MY Sienna [08/2018 -        ]; NETWORKING: CAN COMMUNICATION SYSTEM: DIAGNOSIS SYSTEM ).

Result

Result

Proceed to

CAN communication DTC is not output

A

CAN communication DTC is output

B

B

GO TO CAN COMMUNICATION SYSTEM 2016 MY Sienna [12/2015 - 08/2016]; NETWORKING: CAN COMMUNICATION SYSTEM: HOW TO PROCEED WITH TROUBLESHOOTING 2017 MY Sienna [08/2016 - 11/2017]; NETWORKING: CAN COMMUNICATION SYSTEM: HOW TO PROCEED WITH TROUBLESHOOTING 2018 - 2020 MY Sienna [11/2017 -        ]; NETWORKING: CAN COMMUNICATION SYSTEM: HOW TO PROCEED WITH TROUBLESHOOTING

A

2.

CONFIRM DTC OUTPUT (LIGHT CONTROL SENSOR CIRCUIT)

(a) Check if DTC B1244 is output (See page 2016 - 2020 MY Sienna [12/2015 -        ]; LIGHTING (EXT): LIGHTING SYSTEM: DTC CHECK / CLEAR ).

Result

Result

Proceed to

B1244 is not output

A

B1244 is output

B

B

GO TO LIGHTING SYSTEM

(See page 2016 - 2017 MY Sienna [12/2015 - 11/2017]; LIGHTING (EXT): LIGHTING SYSTEM: DIAGNOSTIC TROUBLE CODE CHART 2018 - 2020 MY Sienna [11/2017 -        ]; LIGHTING (EXT): LIGHTING SYSTEM: DIAGNOSTIC TROUBLE CODE CHART )

A

3.

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 that the taillights and low beam headlights.

OK:

The taillights and low beam headlights come on.

(e) Uncover the automatic light control sensor.

(f) Check that the low beam headlights and taillights.

OK:

The low beam headlights and taillights go off.

Result

Result

Proceed to

Automatic light control system operates normally

A

Automatic light control system does not operate normally

B

B

CHECK LIGHTING SETTING

(See page 2016 - 2017 MY Sienna [12/2015 - 11/2017]; LIGHTING (EXT): LIGHTING SYSTEM: CUSTOMIZE PARAMETERS 2018 - 2020 MY Sienna [11/2017 -        ]; LIGHTING (EXT): LIGHTING SYSTEM: CUSTOMIZE PARAMETERS )

A

4.

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

(a) Replace the main body ECU (multiplex network body ECU) with a new or a normal one (See page 2016 - 2020 MY Sienna [12/2015 -        ]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL ).

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 (multiplex network body ECU). If the meter does not dim when the light control switch is in the tail, head, or AUTO position at night, it may be for either of 2 reasons. The first reason is that the main body ECU (multiplex network body ECU) does not send an auto dimmer signal. The second is that the meter CPU does not dim the meter illumination even though the meter CPU receives an auto dimmer signal.

OK

END (MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) WAS DEFECTIVE)

NG

REPLACE COMBINATION METER ASSEMBLY