Malfunction Indicator Lamp (Service Engine Soon or Check Engine Lamp)

DIAGNOSTIC FUNCTION

MALFUNCTION INDICATOR LAMP (SERVICE ENGINE SOON OR CHECK ENGINE LAMP)





Among the on-board diagnostic items, Malfunction Indicator Lamp (SERVICE ENGINE SOON or Check Engine Lamp) illuminates to notify the driver of an emission control malfunction.
However, when an irregular signal returns to normal and the engine control module judges that it has returned to normal, the Malfunction Indicator Lamp (SERVICE ENGINE SOON or Check Engine Lamp) will switch off.
Among the on-board diagnostic items, the Malfunction Indicator Lamp (SERVICE ENGINE SOON or Check Engine Lamp)illuminates to notify the driver of an emission control malfunction. However, when an irregular signal returns to normal and the powertrain control module judges that it has returned to normal, the Malfunction Indicator Lamp (SERVICE ENGINE SOON or Check Engine Lamp) will be switched off. When the ignition switch is in the ON position, the indicator lamp should be illuminated. When the engine starts, the indicator lamp should be extinguished.
NOTE:
When the Transaxle Control Module (TCM) detects malfunctions related to the CVT, the Malfunction indicator Lamp (SERVICE ENGINE SOON or Check Engine Lamp) is also illuminated.

Items Indicated by the Malfunction Indicator Lamp (SERVICE ENGINE SOON or Check Engine Lamp)













NOTE:
If the Malfunction Indicator Lamp (SERVICE ENGINE SOON or Check Engine Lamp) illuminates because of a malfunction of the engine control module (ECM), communication between the scan tool MB991958
(M.U.T.-III sub assembly) and the ECM is impossible. In this case, the diagnostic trouble code cannot be read.

NOTE:
After the ECM has detected a malfunction, the Malfunction Indicator Lamp (SERVICE ENGINE SOON or Check Engine Lamp) illuminates when the engine is next turned on and the same malfunction is re-detected. However, for items marked with a "*1" in the DTC NO. column, the Malfunction Indicator Lamp (SERVICE ENGINE SOON or Check Engine Lamp) illuminates only on the first detection of the malfunction.

NOTE:
The codes marked with a "*2" in the diagnostic trouble code number column have the following two conditions for illuminating the Malfunction Indicator Lamp (SERVICE ENGINE SOON or Check Engine Lamp).

- In case that the misfire causing the damaged catalyst is detected, the Malfunction Indicator Lamp (SERVICE ENGINE SOON or Check Engine Lamp) is illuminated at the time.
- In case that the misfire deteriorating the exhaust gas is detected, the Malfunction Indicator Lamp (SERVICE ENGINE SOON or Check Engine Lamp) is illuminated when the same malfunction is redetected after the next engine start.

NOTE:
Even if the malfunction is not detected when the ECM monitors the malfunction three consecutive times* after the Malfunction Indicator Lamp (SERVICE ENGINE SOON or Check Engine Lamp) illuminates, turn off the Malfunction Indicator Lamp (SERVICE ENGINE SOON or Check Engine Lamp) when the engine starts next time.

*: In this case, "one time" in monitoring the malfunction means the period from the time of the current engine start to the time of the next engine start. "One time" in monitoring the misfire or the fuel system malfunction means the time when the operating conditions (such as the engine speed or the engine coolant temperature) becomes similar operating conditions of the first detected malfunction.