Do I Need A Fuel Pump Control Module?

Potential complaints:
Loss of ability, fuel pressure lost, engine light on, limp home function, engine won't showtime

Possible OBD diagnostic trouble codes:

P025A ... P025D, P027A ... P027D, P064A, P069E	fuel pump control unit
P0087	fuel system track/system force per unit area too low
P0191	sender for fuel pressure – unplausible signal

Possible causes:
There are other possible causes in improver to a failure in the fuel pump control unit:

Fuel pressure sensor faulty
Fuel pump relay faulty
Wiring harness faulty
Blocked fuel filter
Empty fuel tank (due to wrong tank indicator)
Fuel pump faulty

During the replacement, note that:

The feature bend saved in the fuel pump control unit is specific to the vehicle engine and model. During replacement, the imprinted software version (A) must exist equal to or higher than the installed unit.

Depending on the vehicle, the fuel pump control unit must be taught in the engine command unit. To improve the start behaviour, the fuel pump is often triggered for a few seconds when the commuter door is opened, causing pressure to build up in the fuel system – fifty-fifty though the ignition is still switched off.

This ways that, for the period while the fuel pump control unit is being replaced, the relevant fuse must exist removed if the bombardment is not disconnected (e.g. Audi A3: no. 27, see relevant circuit diagrams).

Attention:

Electrical components can be damaged past electrostatic supercharging. Never touch electrical contacts straight.

Demand-based fuel supply (schematic) — Need-based fuel supply (schematic)
1 Pressure sensor (loftier pressure)
2 Injection nozzles
3 Camshaft
four Loftier-pressure pump
5 Pressure sensor (low force per unit area)
vi Fuel filter with pressure level regulator
7 Bus signal
8 Pulse width modulation signal
9 Engine control unit
10 Fuel pump control unit
11 Fuel delivery module

Background information

In the case of an "unregulated" fuel supply, the fuel pump e'er delivers at maximum performance in the fuel tank. Excess fuel flows back into the fuel tank via the return line.

With "regulated" or "demand-based" fuel supply, the fuel pump (11) is triggered by the fuel pump control unit of measurement (10) with a pulse width modulation signal (PWM point).

Advantages:

Only the required amount of fuel is supplied.
The fuel is heated less, reducing the take chances of vapour locks.
Noise reduction
Reduced power consumption, resulting in fuel savings

The fuel pump in the fuel tank (eleven) conveys the fuel to the low-force per unit area system of the high-pressure pump (4). The fuel pressure in the depression-pressure organisation is between 0.5 and 5 bar during normal operation. During a cold get-go and a warm engine commencement, the fuel pressure is increased to up to 6.5 bar: During a cold outset, this creates a higher starting pressure level in the highpressure organization, resulting in a quicker engine outset. During a warm outset, the increased pressure prevents fuel vapour locks.

A return side may be nowadays, still, e.g. for operating suction jet pumps in the saddle tank.