Toyota Tundra Service Manual: On-vehicle Inspection

ON-VEHICLE INSPECTION

PROCEDURE

1. INSPECT INDICATOR LIGHT

(a) Inspect the 4HI Indicator Light:

(1) Start the engine.

(2) Change the 4WD control switch from 2WD to 4H.

(3) Check the 4HI indicator light.

OK:

The 4HI indicator light comes on or the 4HI indicator light comes on after it is blinking.

If the result is not as specified, inspect the switch, four wheel drive control ECU and transfer shift actuator assembly.

If there is a malfunction, inspect the switch, ECU, transfer shift actuator and A.D.D. actuator. If the system is normal, there may be a malfunction in the CAN communication system or combination meter. In this case, first check the CAN communication system (See page ). Then check the combination meter (See page ) and touch select 2-4 and high-low system (See page ).

(b) Inspect the 4LO Indicator Light:

(1) Start the engine.

(2) Move the shift lever to N.

(3) Change the 4WD control switch from 2WD to 4H. Then change it from 4H to 4L after the 4HI indicator light illuminates (after 4H switch completion).

(4) Check the 4LO indicator light.

OK:

The 4LO indicator light comes on or the 4LO indicator light comes on after it is blinking.

If there is a malfunction, inspect the switch, ECU and actuator. If the system is normal, the combination meter may be malfunctioning.

2. INSPECT TRANSFER POSITION SWITCH

(a) Remove the transfer position switch with its connector still connected (See page TF-89).

(b) Measure the voltage according to the value(s) in the table below. Standard Voltage: Tester Connection Switch Condition Specified Condition J129-2 (2-4) - Body ground Ignition switch ON 2WD position Below 1 V Ignition switch ON 4H position Below 1.5 V Ignition switch ON 4L position 10.5 to 14 V J129-3 (LO) - Body ground Ignition switch ON 2WD position 10.5 to 14 V Ignition switch ON 4H position Below 1.5 V Ignition switch ON 4L position Below 1 V Text in Illustration *a Component with harness connected (Transfer Position Switch)