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Secondary air injection function - GF14.30-P-3012F

ENGINE 120.982 /983 

Fig 1: Secondary Air Injection Function Diagram - Engine 120.982 /983
G04732209

Secondary air injection ensures that the catalytic converter heats up more rapidly to its operating temperature and thus improves the emission levels during the warming-up phase.

Function 

The air pump switchover valve (Y32) and the electromagnetic clutch of the air pump (60) are actuated simultaneously by the ME-SFI control module (N3/12) for a maximum of 150 seconds after engine start if:

Actuation of the air pump electromagnetic coupling (Y33) creates a positive connection to the belt pulley driven by the poly V-belt. The air pump (vane cell pump) is driven.

The pump draws in air through a maintenance-free filter and pumps it to the air shutoff valve.

The air pump shutoff valve switches the intake manifold pressure to the air shutoff valve (126, 126a). This opens and the air supplied by the air pump is forced into the exhaust manifold.

The injected air reacts with hot exhaust gases in the exhaust tract. Oxidation of the carbon monoxide (CO) and hydrocarbon (HC) takes place and results in an additional increase in the exhaust temperature.

REFER TO BASIC KNOWLEDGE ME-SFI control module arrangement/task/ design/function   GF07.61-P-5000F
REFER TO BASIC KNOWLEDGE Air pump arrangement/task/design/function   GF14.30-P-3100F 
REFER TO BASIC KNOWLEDGE Crankshaft position sensor arrangement/task/ design/function   GF07.04-P-4116F
REFER TO BASIC KNOWLEDGE Coolant temperature sensor arrangement/task/ design/function   GF07.04-P-5026F
REFER TO BASIC KNOWLEDGE Air shutoff valve arrangement/task/function   GF14.30-P-4028F 
REFER TO BASIC KNOWLEDGE Air pump switchover valve arrangement/task/design/function   F14.30-P-3103F
REFER TO BASIC KNOWLEDGE Check valve (injected air) arrangement/task/design/function   GF14.30-P-4029F 
REFER TO BASIC KNOWLEDGE Secondary air injection relay arrangement/task/ design/function   GF14.30-P-3101F 
REFER TO BASIC KNOWLEDGE Air pump electromagnetic coupling task/ function   GF14.30-P-3104F
REFER TO BASIC KNOWLEDGE EA/CC/ISC actuator arrangement/task/design/ function   GF30.22-P-4010F
REFER TO BASIC KNOWLEDGE Lambda control function   GF07.61-P-4022F
REFER TO BASIC KNOWLEDGE Base module arrangement/task/design/function   GF54.21-P-4013L
REFER TO BASIC KNOWLEDGE Three-way catalytic converter design/function   GF49.10-P-3002F