SFI SYSTEM > DIAGNOSIS SYSTEM

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DESCRIPTION


  1. EURO-OBD (EUROPE)


    1. FI02547
      When troubleshooting Europe On-Board Diagnostic (Euro-OBD) vehicles, the vehicle must be connected to an OBD scan tool (complying with ISO 15765-4). Various data output from the vehicle's ECM can then be read.
      Euro-OBD regulations require that the vehicle's on-board computer illuminates the Malfunction Indicator Lamp (MIL) on the instrument panel when the computer detects a malfunction in:

    1. The emission control system/components.

    2. The power train control components (which affect vehicle emissions).



      3. A103811E09

    3. The computer.
      In addition, the applicable Diagnostic Trouble Codes (DTCs) prescribed by ISO 15765-4 are recorded in the ECM memory
      If the malfunction does not reoccur in 3 consecutive trips, the MIL turns off automatically but the DTCs remain recorded in the ECM memory.
      To check DTCs, connect the intelligent tester or OBD scan tool to the Data Link Connector 3 (DLC3) of the vehicle. The scan tool displays DTCs, the freeze frame data and a variety of engine data.
      The DTCs and freeze frame data can be erased with the scan tool (Click here).

  2. M-OBD (EXCEPT EUROPEAN SPEC.)


    1. FI02547
      When troubleshooting Multiplex On-Board Diagnostic (M-OBD) vehicles, the vehicle must be connected to the intelligent tester. Various data output from the ECM can then be read.
      OBD regulations require that the vehicle's on-board computer illuminates the MIL on the instrument panel when the computer detects a malfunction in:

    1. The emission control system/components.

    2. The power train control components (which affect vehicle emissions).

    3. The computer.
      In addition, the applicable DTCs are recorded in the ECM memory.
      If the malfunction does not reoccur in 3 consecutive trips, the MIL turns off automatically but the DTCs remain recorded in the ECM memory.


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 as an option for technicians. In check mode, 1 trip detection logic is used for simulating malfunction symptoms and increasing the system's ability to detect malfunctions, including intermittent problems (intelligent tester only).

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

FREEZE FRAME DATA
  1. Freeze frame data records the engine conditions (fuel system, calculated engine load, engine coolant temperature, fuel trim, engine speed, vehicle speed, etc.) when malfunctions are 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.

Data Link Connector 3 (DLC3)

  1. A082779E49
    The vehicle's ECM uses the ISO 15765-4 for communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 15765-4 format.

Symbols
Terminal No.
Names
Reference terminal
Results
Condition
SIL
7
Bus "+" line
5 - Signal ground
Pulse generation
During transmission
CG
4
Chassis ground
Body ground
1 Ω or less
Always
SG
5
Signal ground
Body ground
1 Ω or less
Always
BAT
16
Battery positive
Body ground
9 to 14 V
Always
CANH
6
CAN "High" line
CANL
54 to 69 Ω
Engine switch off
CANH
6
CAN "High" line
Battery positive
1 MΩ or higher
Engine switch off
CANH
6
CAN "High" line
CG
1 kΩ or higher
Engine switch off
CANL
14
CAN "Low" line
Battery positive
1 MΩ or higher
Engine switch off
CANL
14
CAN "Low" line
CG
1 kΩ or higher
Engine switch off

HINT:
Connect the cable of the intelligent tester to the DLC3, turn the engine switch on (IG) and attempt to use the intelligent tester. If the display indicates a communication error message, a problem exists on the vehicle side or the tester side.
  1. If communication is normal when the tester is connected to another vehicle, inspect the DLC3 on the original vehicle.
  2. If communication is still impossible when the tester is connected to another vehicle, the problem is probably in the tester itself. Consult the Service Department listed in the tester's instruction manual.


BATTERY VOLTAGE

Battery voltage:
11 to 14 V

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

Malfunction Indicator Lamp (MIL)

  1. The MIL is illuminated when the engine switch is first turned on (IG) (the engine is not running).

  2. The MIL should turn OFF when the engine is started. If the MIL remains illuminated, the diagnosis system has detected a malfunction or abnormality in the system.

HINT:
If the MIL is not illuminated when the engine switch is first turned on (IG), check the MIL circuit (Click here).