Air Injection Pump: Description and Operation

NOTE As of approximately 09/94, the electrical AIR pump known from model 202 is installed on the 129, 140 with engine 104. At the same time a check valve is also installed into the AIR shut-off valve. The AIR motor (M33) is actuated by the engine control module (N3/4) via the AIR relay module (K17).
A check valve will be integrated into the AIR shut-off valve on all models with engine 104.

Model 202 Air Injection Pump





Located under the generator.

The maximum current draw is 35 A at 12 V and a maximum back pressure of 150 mbar.

The AIR check valve was eliminated. This function is taken over by the secondary air injection (AIR) shut-off valve





Activation of the electrical AIR pump (M33) is accomplished by the engine control module (HFM-SFI) (N3/4) via the AIR relay module (K17).