Description of On-Board Diagnostics

SELF-DIAGNOSIS
The ECM monitor the input/output signals (some signals at all times and the others under specified conditions). When the ECM detects an irregularity, it memorize the diagnostic trouble code, and outputs the signal to the self-diagnosis output terminal. The diagnosis results can be read out by the Generic Scan Tool (GST). Diagnostic trouble code (DTC) will remain in the ECM as long as battery power is maintained. The diagnostic trouble code will however, be erased when the battery negative terminal or the Engine Control Module (ECM) connector is disconnected or erased by the Generic Scan Tool.

CHECKING PROCEDURE (SELF-DIAGNOSIS)

NOTE:
(1) When battery voltage is low, diagnostic trouble codes can not be read. Be sure to check the battery for voltage and other conditions before starting the test.
(2) Diagnosis memory is erased if the battery or the ECM connector is disconnected. Do not disconnect the battery before the diagnostic trouble codes are completely read and recorded.







MALFUNCTION INDICATOR LAMP (MIL)
An On Board Diagnostic lamp comes on to notify the driver that there is a problem in the vehicle.
However MIL will go off automatically after 3 sequential driving cycles without the same malfunction.
Immediately after the ignition switch is turned on (ON position), the malfunction indicator light is lit continuously to indicate that the malfunction indicator light operates normally.
Following Items will be Indicated by the MIL
- Catalyst
- Fuel system
- Mass Air Flow Sensor
- Intake Air Temperature Sensor
- Engine Coolant Temperature Sensor
- Throttle Position Sensor
- Upstream Oxygen Sensor
- Downstream Oxygen Sensor Heater
- Downstream Oxygen Sensor
- Upstream Oxygen Sensor Heater
- Injector
- Misfire
- Crankshaft Position Sensor
- Camshaft Position Sensor
- Evaporative Emission Control System
- Vehicle Speed Sensor
- Idle Control Valve
- Power Supply
- ECM
- MT/AT encoding
- Acceleration Sensor
- MIL-on Request Signal
- Power Stage
- Canister Close Valve
- Fuel Tank Pressure Sensor