Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Fuel Supply Overview
As with current gasoline fuel injection systems, there is an electric fuel pump located in the fuel tank. The fuel pump supplies the needed low pressure fuel to feed the mechanical high-pressure pump.
| Index | Explanation |
|---|---|
| 1 | Fuel filler neck |
| 2 | Left hand service opening |
| 3 | Fuel return line |
| 4 | Fuel filter with heating system |
| 5 | Right hand service opening |
| 6 | Filler vent |
| 7 | Electric fuel pump module (EKP) |
The fuel tank is equipped with two chambers and, on modern vehicles, is made from plastic. The electric fuel pump on the diesel engines is driven by the EKP module.
Similar to BMW gasoline engines, the fuel system on the vehicles equipped with diesel engines share much of the same "low pressure" system components.
However, there are some distinct differences with the diesel engine.
These are:
- The system includes a fuel return line
- The breather system is significantly simpler
- There is no carbon canister (AKF) and no fuel tank leakage diagnosis module (DMTL)
- There is no pressure regulator
- The fuel filter is not located in the fuel tank.
The design layout of the fuel supply systems in the E70 and E90 are described in the following.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.