Contents: Examination ⇓ Self-diagnosis ⇓
The malfunction indicator lamp lights up to warn the driver that there is a malfunction in the vehicle. However, if the detected malfunction does not occur after 3 consecutive driving cycles, the lamp goes out. The lamp lights up immediately after the ignition is turned on (without starting the engine), which indicates that it is in good condition.
List of faults that cause the malfunction indicator lamp to light:
- heated oxygen sensor faulty;
- absolute pressure sensor faulty;
- throttle position sensor is faulty;
- coolant temperature sensor is faulty;
- idle speed control is faulty;
- the injectors are faulty;
- the engine control unit is faulty.
Examination
1. Make sure that after turning on the ignition, the lamp lights for about 5 seconds and then goes out.
2. If the lamp does not light, the possible cause is a broken wire, a blown fuse, or a blown lamp itself.
Self-diagnosis
The engine control unit sends control commands to the actuators and processes the signals from the sensors (some commands and signals constantly, while others only under certain conditions). If the ECU detects a deviation from the norm, it records a diagnostic trouble code and sends a signal to the data line connector. The diagnostic result is displayed by the illumination of the malfunction indicator lamp or on the HI-SCAN tool. Diagnostic trouble codes (DTCs) are stored in the ECU memory as long as voltage is supplied from the battery. However, the trouble codes are cleared by disconnecting the battery or disconnecting the ECU connector, or using the HI-SCAN tool.
Note: If the wiring connectors are disconnected from any sensor with the ignition on, a fault code is recorded. In this case, the fault code should be cleared by disconnecting the negative wire "-" from the battery.
(The article is copied from this website: «hyundaibook.ru»)