Toyota Tundra Service Manual: Diagnosis System

DIAGNOSIS SYSTEM

1. DESCRIPTION

The 4 wheel drive control ECU records DTCs when the ECU detects a malfunction in the ECU itself or in system circuits.

The DTCs can be read through the DLC3 of the vehicle. When the system seems to be malfunctioning, use the Techstream to check for malfunctions and perform troubleshooting.

2. CHECK DLC3

(a) Inspect the battery voltage.

Standard voltage:

11 to 14 V

If the voltage is below 11 V, recharge the battery before proceeding.

(b) Check the DLC3 (See page ).

3. FUNCTION OF INDICATOR LIGHT

(a) When a problem occurs in the touch select 2-4 and high-low system, the 4HI and 4LO indicator lights on the combination meter assembly rapidly blink* to inform the driver of the problem.

• *: 0.25 second intervals (0.25 seconds on and 0.25 seconds off)