ME secondary air injection malfunction (causal chain) - fault code description - AD07.61-P-4000-15AA

		Secondary air injection: malfunction (function chain)
1	Fault code ( Readout on generic scan tool)	P2003 (P0410)
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	once per driving cycle
4	Checked signal or status	Closed-loop mixture control
5	Fault setting conditions	Increase in the lambda controlling factor of at least +23%
	Checking duration	approx. 10 seconds
6	Check prerequisites	Engine at idle speed Vehicle stationary Air pump activated at least once after engine start No fault on voltage supply to purge control valve, air pump switchover valve and electric air pump No fault in purge system No fault in throttle valve actuator No misfiring No fault in O2 sensor upstream of TWC, aging No fault in CAN data bus Self-adaptation of the mixture formation not at limit Air pressure more than around 780 hPa (i.e. no test is performed above a height of around 2500 m) Coolant temperature at start -10°C to +45°C Lambda control enabled AC off.
7	Checking procedure	On starting the causal chain, all functions for self-regulation of mixture adjustment are locked, the switchover valve for regeneration is closed and the current lambda controlling factor recorded. This is followed by air injection. The mixture must be made leaner. The lambda control factor reacts in a corresponding manner with an increase of about +23%.
8		If a prerequisite changes during the test, the test is interrupted and started again later.

Air injection for engine 113 

Fig 1: Identifying Air Injection Components - Engine 113

Courtesy of MERCEDES-BENZ USA