Check Engine/Malfunction Indicator Lamp

CHECK ENGINE/MALFUNCTION INDICATOR LAMP
Among the on-board diagnostic items, a check engine/malfunction indicator lamp comes on to notify the driver of the emission control items when an irregularity is detected. However, when an irregular signal returns to normal and the engine control module judges that it has returned to normal, the check engine/malfunction indicator lamp goes out. Moreover, when the ignition switch is turned off, the light goes out Even if the ignition switch is turned on again, the light does not come on until the irregularity is detected.

Here, immediately after the ignition switch is turn on, the check engine/malfunction indicator lamp is lit for 5 seconds to indicate that the check engine/malfunction indicator lamp operates normally.





ITEMS INDICATED BY THE CHECK ENGINE/MALFUNCTION INDICATOR LAMP

CAUTION The check engine/malfunction indicator lamp lights up when the ignition timing adjustment terminal is short- circuited to ground. Consequently, it lights up when the ignition timing adjustment is grounded when adjusting ignition timing, but in this case there is no abnormality.

CHECK ENGINE/MALFUNCTION INDICATOR LAMP INSPECTION
When turning on the ignition switch, check that the light comes on.

NOTE If the light does not come on, check the harness and light for breakage.

ON-BOARD DIAGNOSTIC
The engine control module monitors the input/output signals (some signals at all times and the others under specified conditions) of the engine control module.

When it is noticed that an irregularity has continued for a specified time or longer from when the irregular signal is initially monitored, passing a certain number, the engine control module judges that an irregularity has occurred, memorizes the diagnostic trouble code, and outputs the signal to the on-board diagnostic output terminal.

There are 16 diagnostic items including the normal state, and the diagnostic results can be read out with a Voltmeter or scan tool.

Moreover, since memorization of the diagnostic trouble codes is backed up directly by the battery, the diagnostic results are memorized even if the ignition key is turned off. The diagnostic trouble codes will, however, be erased when the battery terminal or the engine control module connector is disconnected. The diagnostic trouble codes of the engine control module are erased by turning on the ignition switch and sending the diagnostic trouble code erase signal from the scan tool to the engine control module.

CAUTION If the sensor connector is disconnected with the ignition switch turned on, the diagnostic trouble code is memorized. In this case, send the diagnostic trouble code erase signal from the scan tool to the engine control module or disconnect the battery terminal (-) for 10 seconds or more, and the diagnostic memory will be erased.

The 16 diagnostic items are provided as follows, and if plural items are activated, they are all indicated sequentially from the smallest code number.