Description |
If the Gasoline Engine Control system components (sensors, ECM, injector, etc.) fail, interruption to the fuel supply or failure to supply the proper amount of fuel for various engine operating conditions will result. The following situations may be encountered.
1. |
Engine is hard to start or does not start at all. |
2. |
Unstable idle. |
3. |
Poor driveability |
If any of the above conditions are noted, first perform a routine diagnosis that includes basic engine checks (ignition system malfunction, incorrect engine adjustment, etc.). Then, inspect the Gasoline Engine Control system components with the KDS.
|
Malfunction Indicator Lamp (MIL)
[EOBD]
A malfunction indicator lamp illuminates to notify the driver that there is a problem with the vehicle. However, the MIL will go off automatically after 3 subsequent sequential driving cycles without the same malfunction. Immediately after the ignition switch is turned on (ON position - do not start), the MIL will illuminate continuously to indicate that the MIL operates normally.
Faults with the following items will illuminate the MIL.
• |
Catalyst |
• |
Fuel system |
• |
Air Flow Sensor |
• |
Intake Air Temperature Sensor |
• |
Engine Coolant Temperature Sensor |
• |
Throttle Position Sensor |
• |
Heated Oxygen Sensor (Upstream) |
• |
Heated Oxygen Sensor Heater (Upstream) |
• |
Heated Oxygen Sensor (Downstream) |
• |
Heated Oxygen Sensor Heater (Downstream) |
• |
Injector |
• |
Misfire |
• |
Crankshaft Position Sensor |
• |
Camshaft Position Sensor |
• |
Evaporative Emission Control System |
• |
Vehicle Speed Sensor |
• |
Idle Speed Control System |
• |
Power Supply |
• |
ECM/ PCM |
• |
MT/AT Encoding |
• |
Acceleration Sensor |
• |
MIL-ON Request Signal |
• |
Power Stage |
|
[NON-EOBD]
A malfunction indicator lamp illuminates to notify the driver that there is a problem with the vehicle. However, the MIL will go off automatically after 3 subsequent sequential driving cycles without the same malfunction. Immediately after the ignition switch is turned on (ON position - do not start), the MIL will illuminate continuously to indicate that the MIL operates normally.
Faults with the following items will illuminate the MIL
• |
Heated Oxygen Sensor (HO2S) |
• |
Mass Air Flow sensor (MAFS) |
• |
Throttle Position Sensor (TPS) |
• |
Engine Coolant Temperature Sensor (ECTS) |
• |
Idle Speed Control Actuator (ISCA) |
• |
Injectors |
• |
ECM |
|
[INSPECTION]
1. |
After turning ON the ignition key, ensure that the light illuminates for about 5 seconds and then goes out. |
2. |
If the light does not illuminate, check for an open circuit in the harness, a blown fuse or a blown bulb. |
Self-Diagnosis
The ECM monitors the input/output signals (some signals at all times and the others under specified conditions). When the ECM detects an irregularity, it records the diagnostic trouble code, and outputs the signal to the Data Link connector. The diagnosis results can be read with the MIL or the KDS. Diagnostic Trouble Codes (DTC) will remain in the ECM as long as battery power is maintained. The diagnostic trouble codes will, however, be erased when the battery terminal or ECM connector is disconnected, or by the KDS.
|
The relation between DTC and driving pattern in EOBD system
1. |
When the same malfunction is detected and maintained during two sequential driving cycles, the MIL will automatically illuminate. |
2. |
The MIL will go off automatically if no fault is detected after 3 sequential driving cycles. |
3. |
A Diagnostic Trouble Code(DTC) is recorded in ECM memory when a malfunction is detected after two sequential driving cycles. The MIL will illuminate when the malfunction is detected on the second driving cycle. If a misfire is detected, a DTC will be recorded, and the MIL will illuminate, immediately after a fault is first detected. |
4. |
A Diagnostic Trouble Code(DTC) will automatically erase from ECM memory if the same malfunction is not detected for 40 driving cycles.
|