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)
    4WD Control Switch Circuit

    Diagnostic Trouble Code Chart

    See More:

    Toyota Tundra Service Manual > Engine Immobiliser System (w/o Smart Key System): Parts Location
    PARTS LOCATION ILLUSTRATION *1 UNLOCK WARNING SWITCH ASSEMBLY *2 TRANSPONDER KEY COIL *3 TRANSPONDER KEY ECU ASSEMBLY *4 ECM *5 COMBINATION METER ASSEMBLY (SECURITY INDICATOR LIGHT) *6 MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) *7 DRIVER SIDE JUNCTION BLOCK ASSEMBLY - ECU-B NO.1 FUSE - ECU-IG2 NO.3 ...

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    Toyota Tundra Service Manual

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