Description of On-Board Diagnostics

DIAGNOSTIC TROUBLE CODE (DTC) MEMORY

Function
The Engine Control Module (ECM) (J169) for the Fuel Injection and Ignition system is equipped with a Diagnostic Trouble Code (DTC) Memory.

If malfunctions occur in sensors and/or components that are monitored, they are stored in DTC Memory along with data on the type of malfunction. Check DTC Memory to display stored malfunctions.

DTC display occurs after activation of the Scan Tool (ST).

DTC Memory must be erased after the malfunctions have been corrected or repaired.

Malfunctions that affect Oxygen Sensor (O2S) control can only be read accurately after a test drive of at least 5 minutes.

Malfunctions such as intermittent open circuits or loose terminals are stored and displayed as follows:

^ If malfunctions occur for a maximum of 5 seconds, they are stored and considered to be "sporadic" and when displayed, will show the letter code "SP".

^ If malfunctions are present for more than 5 seconds, they are stored as DTCs and will be displayed like a permanent malfunction even though the malfunction is not occuring at the time of the reading.

^ California vehicles are equipped with a Malfunction Indicator (MIL) Lamp.

^ The Malfunction Indicator Lamp in the instrument panel, must light up when the ignition is switched on, and go off when the engine is running.

^ As long as malfunctions occur in the monitored sensors or components and the monitoring conditions are met, the Malfunction Indicator Lamp lights up even with the engine running.