With on-board diagnostics (OBD)
The MIL warning lamp lights up when there are malfunctions in the engine management system. However, the MIL will not come on after three engine starts if the previously detected fault does not reappear. After turning on the ignition (before engine start) the control lamp is constantly on, which indicates the normal operation of the troubleshooting system. Pilot lamp with system «OBD» lights up when there are malfunctions in the following elements of the system:
- catalytic converter;
- fuel system;
- air flow meter;
- absolute pressure sensor in the intake manifold;
- temperature sensor of the air entering the engine;
- coolant temperature sensor;
- throttle position sensor;
- oxygen sensor;
- oxygen sensor heater;
- fuel injectors;
- misfiring;
- crankshaft angle sensor;
- camshaft position sensor;
- fuel vapor recovery system;
- vehicle speed sensor;
- idle speed control valve;
- electrical supply;
- ECM;
- malfunction of the gearbox;
- acceleration sensor;
- MIL signal request;
- power reduction.
Without OBD (OBD)
The MIL warning lamp lights up when there are malfunctions in the engine management system. However, the MIL will not come on after three engine starts if the previously detected fault does not reappear. After turning on the ignition (before engine start) the control lamp is constantly on, which indicates the normal operation of the troubleshooting system.
Pilot lamp without system «OBD–II» lights up when there are malfunctions in the following elements of the system:
- heated oxygen sensor;
- absolute pressure sensor in the intake manifold;
- coolant temperature sensor;
- the engine crankshaft speed control modulator at idle;
- fuel injectors;
- ECM.
Examination
1. After turning on the ignition, the control lamp lights up for 5 seconds, after which it goes out.
2. If the control lamp does not light up, check up an electric circuit of a lamp, integrity of a safety lock and serviceability of a lamp.
Self-diagnosis
The ECM constantly monitors input and output signals and other signals under certain conditions. When a malfunction is detected, the ECM stores a DTC in memory and provides a code output to the diagnostic connector.
Diagnostic codes (DTC) can be read using a test lamp or a HI-SCAN scanner. Diagnostic codes remain in the memory until the wires are disconnected from the battery terminals or the connector is disconnected from the ECM, and until they are erased using a scanner.
Attention! If the connector is disconnected with the ignition on, a DTC will be stored in the memory. In this case, disconnect the cable from the negative terminal of the battery for more than 15 seconds, as a result of which the diagnostic memory will be erased.