Toyota Tundra Service Manual: Illumination for Panel Switch does not Come on with Tail Switch ON

PROCEDURE

1.	CHECK VEHICLE SIGNAL (OPERATION CHECK)

(a) Enter the "Vehicle Signal Check Mode" screen. [Refer to Check Vehicle Signal in Operation Check (See page )]

(b) Check that the display for "TAIL" changes between ON and OFF according to the light control switch operation.

OK:

Light Control Switch	Display
Tail or head	ON
Off	OFF

HINT:

This display is updated once per second. As a result, it is normal for the display to lag behind the actual switch operation.

Result

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

Toyota Tundra Service Manual > Touch Select 2-4 And High-low System: Automatic Disconnecting Differential Motor Limit Switch Circuit (P17A4)
DESCRIPTION When the A.D.D. actuator is switching between 2WD and 4WD, the DL1 and DL2 terminals of the limit switch are in one of the ON/OFF combinations listed in the table below. Terminal In 2WD Switching between 2WD and 4WD In 4WD DL1 OFF (OPEN) ON (GND) ON (GND) DL2 ON (GND) ON (GND) OFF (OPEN) ...

Toyota Tundra Owners Manual