DTC Description

Fault Memory & Actuation Of MIL - Misfire (emission limit) after 2 consecutive driving cycles with fault. Misfire (harmful to TWC) MIL flashes immediately.
Frequency Of Testing - Continuous.
Checked Signal Or Status - Number of recognized combustion misfires (recognition by means of uneven running).
Limit Value - Maximum of 20 combustion misfires within 1000 engine revolutions. Maximum of 4-35 combustion misfires within 200 engine revolutions (depends on engine speed and load). As an example, 4 misfires from moderate engine speed and load, or 35 misfires at idle without load.
Test Conditions - Engine speed approximately 450-6000 RPM, change in engine speed less than 1900 RPM per second, change in load less than 50 percent per second, engine has been started for at least 5 seconds, no Electronic Stability Program (ESP) control intervention, sensor wheel adaptation has already taken place in overrun mode, no road surface irregularities recognized (determined by comparison of wheel speeds by Acceleration Slip Regulation/Electronic Stability Program (ASR/ESP) control module through Controller Area Network (CAN), no fault in camshaft hall-effect sensor signal and no inertia fuel shutoff.

NOTE: If limit value for misfire "harmful to TWC" is exceeded, the MIL flashes immediately. If too many combustion misfires occur in one cylinder, the cylinder is switched off (cylinder selective fuel shut off). After the affected cylinders are shut off, the MIL changes from flashing to continuously lit until next time the engine is started. If combustion misfires are recognized, the fault code P0460 or P0462 is set if fuel tank level is too low (fuel reserve indicator light is on). Combustion misfires due to a shortage of fuel are recognized by means of this additional information.

NOTE: If misfires are recognized in one cylinder, using scan tool, switch off one ignition circuit after the other for further trouble shooting of the dual ignition system. After switching off one ignition circuit, the uneven running value will hardly change if the active ignition circuit is okay. If the uneven running value changes, continue trouble shooting in the active ignition circuit. Check spark plug, ignition wire and ignition coil.

NOTE: Misfiring may be caused by many faults in the fuel injection system. Usually a misfiring fault is stored with faults pertaining to other components. An engine mechanical fault could also cause a misfire condition.