ECD SYSTEM > DIAGNOSIS SYSTEM

for Preparation Click here



DESCRIPTION
A093827E01

  1. When troubleshooting a Euro-OBD (On-Board Diagnostic) vehicle, an intelligent tester or OBD scan tool must be connected to the DLC3 (Data Link Connector 3) of the vehicle. Various data in the vehicle's ECM (Engine Control Module) can be then read.

  2. Euro-OBD regulations require that the vehicle's on- board computer illuminates the MIL (Malfunction Indicator Lamp) in the instrument panel when the computer detects malfunctions in:

    1. The emission control system and components.

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

    3. The computer itself. If the malfunction does not recur in 3 consecutive trips, the MIL turns off automatically but the DTCs remain recorded in the ECM memory.

  3. To check the DTCs, connect an intelligent tester to the DLC3. The tester displays DTCs, freeze frame data, and a variety of engine data. The DTCs and freeze frame data can be cleared with the tester (refer to DTC Check/Clear (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 next subsequent drive cycle, the MIL is illuminated (2nd trip).

FREEZE FRAME DATA
The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

DLC3 (Data Link Connector 3) (Click here)

INSPECT BATTERY VOLTAGE
If the voltage is below 11 V, recharge or replace the battery before proceeding to the next step.

Standard Voltage:
11 to 14 V


CHECK MIL


    A093827E01

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

    HINT:
    If the MIL is not illuminated, check the MIL circuit (Click here).

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


ALL READINESS

HINT:
  1. With "All Readiness" you can check whether or not the DTC judgment has been completed by using the intelligent tester.
  2. You should check "All Readiness" after simulating malfunction symptoms or for validation after finishing repairs.

  1. Connect the intelligent tester to the DLC3.

  2. Turn the ignition switch to ON and the tester on.

  3. Clear the DTCs (Click here).

  4. Turn the ignition switch off and wait for 30 seconds.

  5. Perform the DTC judgment driving pattern to run the DTC judgment.

  6. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

  7. Input the DTCs to be confirmed.

  8. Check the DTC judgment result.


Tester Display
Description
NORMAL
  1. DTC judgment completed
  2. System normal
ABNORMAL
  1. DTC judgment completed
  2. System abnormal
INCOMPLETE
  1. DTC judgment not completed
  2. You should perform driving after confirming DTC enabling conditions
UNKNOWN
  1. Unable to perform DTC judgment
  2. Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit