Misfires - fault code description - ME - AD07.61-P-4000-11BA

		Misfire, emission limit
1	Fault code	P2043 Sum (P0300)
	( Readout on generic scan tool)	P2044 Misfires on cylinder 1 (P0301) P2047 Misfires on cylinder 2 (P0302) P2049 Misfires on cylinder 3 (P0303) P2046 Misfires on cylinder 4 (P0304) P2045 Misfires on cylinder 5 (P0305) P2048 Misfires on cylinder 6 (P0306) P204A Misfires on cylinder 7 (P0307) P204B Misfires on cylinder 8 (P0308)
2	Fault storage	after expiry of test duration and fault
	Actuation of the engine diagnosis indicator lamp (EURO3/4) or CHECK ENGINE (MIL) malfunction indicator lamp	following two successive driving cycles with faults
3	Checking frequency	Continuous
4	Checked signal or status	Number of detected combustion misfires (detection via a smooth operation assessment)
5	Fault setting conditions	A maximum of 17 combustion misfires within 1000 engine revolutions
	Limit value for emission limit	Ultra low emission vehicle: a maximum of 17 combustion misfires within 1000 engine revolutions.
6	Check prerequisites	engine speed approx. 500 to 6250 rpm engine speed change less than 1500 rpm per second load change less than 50% per second no ESP control intervention function no road surface irregularities recognized (via CAN by ESP control unit, determined via comparison of wheel speeds) no fault in the signal from the camshaft Hall sensor no deceleration fuel shutoff engine load more than 17% sensor wheel adaptation already performed in deceleration phase
7		If too many misfires occur at a cylinder, the cylinder is cut off (cylinder selective fuel cutoff). Misfires through faults in the ignition system  If ignition does not take place misfiring occurs. If faults on the ignition system are also stored in addition to the misfire faults then begin with troubleshooting in the ignition system. Maximum permissible deviation from smooth running on a cylinder of approx. 3 ms 2 . If this value is exceeded then determine the ignition circuit causing this through switching off the ignition circuit as follows: Switch off an ignition circuit (a or b) using STAR DIAGNOSIS. Observe the smooth running value on the effected cylinder. The value only changes by a minimal amount (up to approx. 2 ms 2 ): the ignition circuit which is still switched in is fault-free. The value changes strongly (above approx. 2 ms 2 ): the ignition circuit which is still switched in has a fault; check the spark plug, ignition line, ignition coil. Misfires after cylinder shutoff OFF  After switching off the cylinder shutoff the misfire detection is monitored to see whether all exhaust valves and intake valves open again. Misfires due to fuel starvation  If combustion misfires are recognized, another fault code P203A (P0460) is output if the level in the fuel tank is too low. This information suggests combustion misfires due to fuel starvation. Misfiring because of miscellaneous causes  Combustion misfires may be caused by many faults in the injection system. Other component or function faults are usually stored, in addition to the misfire fault, in this case. The cause may also be due to faults in the engine mechanics.

Engine 113 

Cylinder arrangement and ignition firing order 

Fig 1: Identifying Cylinder Arrangement And Ignition Firing Order - Engine 113

Courtesy of MERCEDES-BENZ USA