1. The engine starts with difficulty or does not start.
2. Inconsistent idle speed.
3. The engine does not develop full power.
If any of the above conditions are noted, first perform the self-diagnosis check and the basic check of the engine systems (ignition system malfunction, incorrect engine adjustments, etc.), and then check the components with the HI SCAN scan tool.
Notes:
1) Before removing or installing any part, read the diagnostic trouble codes, then disconnect the negative battery terminal.
2) Before disconnecting the battery terminal, turn the ignition switch to the "OFF" position. Disconnecting and connecting the battery terminal while the engine is running and the ignition switch is in the "ON" position may cause damage to the ECM.
3) The shield of the control cable between the ECM and the oxygen sensor is grounded to the body to prevent interference with radio reception from the ignition system. If the shield of the cable is damaged, the cable must be replaced.
4) When checking the generator for charging, do not disconnect the positive battery terminal to prevent damage to the ECM due to high voltage.
5) When charging the battery with an external charger, disconnect the vehicle power cables from the battery to protect the ECM.
(Original version of the article on the website hyundaibook.ru)