Malfunction Indicator Lamp: Description and Operation

The check engine/malfunction indicator lamp comes on to notify the driver of emission control items when an irregularity is detected. When the engine control module judges that irregular signal has returned to normal the check engine/malfunction indicator lamp goes out. Moreover, when the ignition switch is turned off, the light goes out. When the ignition switch is turned on again, the light does not come on until the irregularity is detected. Immediately after the ignition switch is turned on, the check engine/malfunction indicator lamp is lit for 5 seconds to indicate that it is operating normally.

ITEMS INDICATED BY THE CHECK ENGINE/MALFUNCTION INDICATOR LAMP
- Engine control module
- Oxygen sensor
- Volume air flow sensor
- Intake air temperature sensor
- Throttle position sensor (TPS)
- Engine coolant temperature sensor
- Idle speed control motor position sensor
- Crankshaft position sensor
- Camshaft position sensor
- Barometric pressure sensor
- Ignition timing adjustment signal
- Injector
- Fuel pump
- EGR system

CAUTION: The check engine/malfunction indicator lamp lights up when the ignition timing adjustment terminal is short-circuited to ground when adjusting ignition timing In this case there is no abnormality.