ECD SYSTEM (w/ EGR Cooler Bypass Valve) DIAGNOSIS SYSTEM

EURO-OBD

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 illuminate the Malfunction Indicator Lamp (MIL) on the instrument panel when the computer detects a malfunction in:

1. The emission control system components

2. The powertrain control components (which affect vehicle emissions)

3. The computer

   In addition, if 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 an 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 the scan tool. Click here

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. Click here

2 TRIP DETECTION LOGIC

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 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 running or stopped, 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.

INSPECT BATTERY VOLTAGE

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

CHECK MIL

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

   Tech Tips

   If the MIL is not illuminated, check the MIL circuit. (Refer to MIL circuit on page Click here)

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