Automatic Transmission System Diagnosis System

  1. DESCRIPTION

  1. NORMAL MODE AND CHECK MODE

  1. 2 TRIP DETECTION LOGIC

  1. FREEZE FRAME DATA

  1. CHECK MIL

Automatic Transmission System -- Diagnosis System



DESCRIPTION
When troubleshooting Multiplex OBD (M-OBD) vehicles, the vehicle must be connected to the intelligent tester. Various data output from the vehicle's Transmission Control Module (TCM) can then be read.
The Malfunction Indicator Lamp (MIL) illuminates when the vehicle's on-board computer detects a malfunction in the computer itself or in drive system components. In addition, the applicable Diagnostic Trouble Codes (DTCs) are recorded in the TCM memory (Toyota Fortuner RM000000W710JGX.html).
If the malfunction does not reoccur, the MIL stays illuminated until the ignition switch is turned off, and then the MIL turns off when the ignition switch is turned on. However the DTCs remain recorded in the TCM memory.
To check DTCs, connect the tester to the Data Link Connector 3 (DLC3) on the vehicle or connect terminals TC and CG on the DLC3 (DTCs will be displayed on the combination meter).
Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50
Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.A340E Automatic Transmission.Automatic Transmission System.Automatic Transmission System Diagnosis System

NORMAL MODE AND CHECK MODE
The diagnosis system operates in "normal mode" during normal vehicle use. In normal mode, "2 trip detection logic" is used to ensure accurate detection of malfunctions. "Check mode" is also available to technicians as an option. In check mode, "1 trip detection logic" is used for simulating malfunction symptoms and increasing the system's ability to detect malfunctions, including intermittent malfunctions (Toyota Fortuner RM000000W780ATX.html).

2 TRIP DETECTION LOGIC
When a malfunction is first detected, the malfunction is temporarily stored in the TCM memory (1st trip). If the same malfunction is detected during the next subsequent drive cycle, the MIL is illuminated (2nd trip).

FREEZE FRAME DATA
Freeze frame data records the engine conditions (fuel system, calculated engine load, engine coolant temperature, fuel trim, engine speed, vehicle speed, etc.) when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.

CHECK MIL
Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50

  1. The MIL illuminates when the ignition switch is turned on and the engine is not running.

    HINT:
    If the MIL does not illuminate, check the MIL circuit.

  2. When the engine is started, check that the MIL turns off.
    If the lamp remains illuminated, the diagnosis system has detected a malfunction or abnormality in the system.