ME-SFI Fuel Pump Actuation Function

ME-SFI Fuel Pump Actuation Function




Shown on Engine 119
55 Fuel filter
75 Fuel tank
K27 Fuel pump relay module
Model 129, 140, 202, 208
Model 210 as of 3/97
K40 Relay module model 170, model 210 up to 2/97
K40/4 Fuse and relay module
Model 202
Model 210 as of 3/97
Model 163 designation F1
L5 Crankshaft position sensor
M3 Fuel pump (FP)
N3/10 ME-SFI control unit
N16/1 Base module
S2/1 Ignition/starter switch
Y62 Injectors (LH-SFI, HFM-SFI, PEC [LH, HFM, PMS])



Task
Actuating fuel pump at
- Ignition ON: Actuate fuel pump for about 1 s (audible) as a full running protection. An engine start must be completed, however, before repeated actuation of the fuel pump.
- when starting engine via the first signals of the crankshaft position sensor (L5/5 on Engine 120)
When engine running by means of TN engine speed signal.

Design/function
The fuel is actuated through the fuel pump relay.
The fuel pump relay is actuated through a ground signal from the ME control unit. When the contact is closed, the fuel pump (M3) is linked through circuit 87 to circuit 30 (B+). The voltage supply is fused to the fuel pump.
On engine 120, the fuel pump is actuated by the right ME-SFI control unit (N3/12).

Note: If the fuel pump does not run, check the voltage supply of the ME control unit and the fuse of the fuel pump. Check electric connection at fuel pump for corrosion.