Control units for fuel pumps
Instructions for replacement
My check engine light is lit. What could have caused this? Why does the fuel pressure drop? Why does the engine suddenly lose power?
This could be caused by a failure in the fuel pump control unit.
Loss of power, fuel pressure lost, engine light on, limp home function, engine won't start
|P025A ... P025D, P027A ... P027D, P064A, P069E||fuel pump control unit|
|P0087||fuel system rail/system pressure too low|
sender for fuel pressure – unplausible signal
There are other possible causes in addition 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 incorrect tank indicator)
- Fuel pump faulty
With "regulated" or "demand-based" fuel supply, the fuel pump (11) is triggered by the fuel pump control unit (10) with a pulse width modulation signal (PWM signal).
- Only the required amount of fuel is supplied.
- The fuel is heated less, reducing the risk of vapour locks.
- Noise reduction
- Reduced power consumption, resulting in fuel savings
A return side may be present, however, e.g. for operating suction jet pumps in the saddle tank.