Even though Headlights are Turned on Head-unit does not Dim the Display [07/2022 - ]: Procedure

CHECK IMAGE QUALITY SETTING

Select settings icon from the screen.
Select "Screen" to display the settings screen.

Check that the "Automatic" setting on the display adjustment screen is set to on.

Result

Result	Proceed to
"Automatic" setting is set to off.	A
"Automatic" setting is set to on.	B

Result:

CHANGE "Automatic" SCREEN SETTING TO ON

Result:

See step 2

CHECK RHEOSTAT SETTING

Check the rheostat setting.

Result

Result	Proceed to
Set to maximum brightness	A
Set to other than maximum brightness	B

Result:

SETTINGS

Result:

See step 3

CHECK VEHICLE SIGNAL (OPERATION CHECK)

Enter diagnostic mode.

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Refer to DIAGNOSIS SYSTEM [07/2022 - ]

Select "Function Check/Setting" from the "Service Menu" screen.
Select "System Sensors Check" from the "Function Check/Setting I" screen.

Operate the light control switch and check that the display changes between ON and OFF accordingly.

TAIL

Condition	Display
Light control switch OFF	OFF
Light control switch TAIL or HEAD	ON

ADIM/TCAN

Condition	Display
Ignition switch ON, Light control switch TAIL or HEAD, Automatic light control sensor is covered by hand	Dimmed
Ignition switch ON, Light control switch TAIL or HEAD, Automatic light control sensor is not covered by hand	Not dimmed

HINT:

This display is updated once per second.

Result

Result	Proceed to
Normal	A
TAIL signal malfunction	B
The multi-display assembly does not function normally	C
ADIM/TCAN signal malfunction	D

Result:

REPLACE RADIO RECEIVER ASSEMBLY. Refer to REMOVAL [07/2022 - ]

Result:

See step 5

Result:

GO TO CAN COMMUNICATION SYSTEM. Refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2018 - ]

Result:

See step 4

CHECK HARNESS AND CONNECTOR (ILL+ CIRCUIT)

Disconnect the F1 radio receiver assembly connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
F1-1 (GND1) - Body ground	Ignition switch ON, Light control switch TAIL or HEAD	Below 1 Ω

Measure the voltage according to the value(s) in the table below.

Standard Voltage

Tester Connection	Condition	Specified Condition
F1-25 (ILL+) - Body ground	Ignition switch ON, Light control switch TAIL or HEAD	11 to 14 V

Result

Proceed to
OK
NG

Result:

REPLACE RADIO RECEIVER ASSEMBLY. Refer to REMOVAL [07/2022 - ]

Result:

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK HARNESS AND CONNECTOR (ILL+ CIRCUIT AND BODY GROUND)

Disconnect the F6 multi-display assembly connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
F6-13 (GND1) - Body ground	Always	Below 1 Ω

Measure the voltage according to the value(s) in the table below.

Standard Voltage

Tester Connection	Condition	Specified Condition
F6-2 (ILL) - Body ground	Always	11 to 14 V

Result

Proceed to
OK
NG

Result:

REPLACE MULTI-DISPLAY ASSEMBLY. Refer to REMOVAL [07/2022 - ]

Result:

REPLACE OR REPLACE HARNESS OR CONNECTOR