Air Injection Pump: Description and Operation
GF14.30-P-2000AMG Component Description For The Electric Air Pump
ENGINE 156.980 in MODEL 164, 251 up to Model Year 8
ENGINE 156.982 in MODEL 209
ENGINE 156.983 in MODEL 211, 219
ENGINE 156.984 in MODEL 216, 221 up to Model Year 8
Location on model 164
M33 Electric air pump
The electric air pump is located at the right front in the engine compartment.
Location for model 209 without code P98 Black Series
M33 Electric air pump
The electric air pump is located at the bottom left behind the front bumper.
Location for model 209 with code P98 Black Series
M33 Electric air pump
The electric air pump is located at the left front in the engine compartment.
Location on model 211, 219
M33 Electric air pump
The electric air pump is located at the bottom left behind the front bumper.
Location on model 216, 221
18 Engine oil heat exchanger
M33 Electric air pump
M45 Engine coolant circulation pump
The electric air pump is located at the front right behind the front bumper.
Location on model 251
M33 Electric air pump
The electric air pump is located at the front right behind the front bumper.
Task
The electric air pump blows fresh air for air injection into the exhaust ducts of the cylinder heads.
Air injection allows afterburning in the exhaust ducts or in the catalytic converters which brings the catalytic converters more quickly up to operating temperature.
Design
The electric air pump is a sliding vane pump with an output of 480 W.
Diagnosis
Air injection can be released for diagnosis with STAR DIAGNOSIS for a max. of 2 minutes (for a warm engine only shortly).
Prior to the next actuation, it is essential to maintain a cooling time of 30 minutes, otherwise the air pump may be damaged (overheated).
Actuation for model 164, 251 (shown is the engine compartment at the right)
F58 Engine compartment fuse and relay box
F58f102 Fuse 102 (circulation pump fuse for coolant for engine oil heat exchanger)
F58kC Coolant circulation pump relay (engine oil heat exchanger)
F58kD Engine circuit 87 relay
F58kE Air pump relay
F58kI Starter relay
The electric air pump is actuated via the air pump relay by the ME-SFI [ME] control unit (N3/10) for a maximum of 40 seconds for released air injection.
The air pump switchover valve (Y32) is also actuated in parallel by the ME-SFI [ME] control unit.
Actuation for model 209, (shown is the engine compartment at the bottom left)
N10/1 Front SAM control unit with fuse and relay module
N10/1kO Air pump relay
N10/1kR Circuit 87 relay, engine
N10/1kS Starter relay
The electric air pump is actuated via the air pump relay by the ME-SFI [ME] control unit (N3/10) for a maximum of 40 seconds for released air injection.
The air pump switchover valve (Y32) is also actuated in parallel by the ME-SFI [ME] control unit.
Actuation for model 211, 219
F82A FP fuse
F82B Air injection fuse
K17 Air injection relay
Figure on left: Trunk on the right except model 211.2 with code 810, Sound system
Figure on right: Trunk on the lower right for model 211.2 with code 810, Sound system
The electric air pump is actuated via the air pump relay by the ME-SFI [ME] control unit (N3/10) for a maximum of 40 seconds for released air injection.
The air pump switchover valve (Y32) is also actuated in parallel by the ME-SFI [ME] control unit.
Actuation for model 216, 221 (shown is the engine compartment at the bottom left)
N10/1 Front SAM control unit with fuse and relay module
N10/1f55 Fuse 55 (air pump fuse)
N10/1kA Air pump relay
N10/1kC Circuit 87 relay, engine
N10/1kH Circuit 50 relay, starter
N10/1kJ Circuit 15 relay, starter
The electric air pump is actuated via the air pump relay by the ME-SFI [ME] control unit (N3/10) for a maximum of 40 seconds for released air injection.
The air pump switchover valve (Y32) is also actuated in parallel by the ME-SFI [ME] control unit.