Caution! When working with the fuel system, observe fire safety measures.
Removal
1. Disconnect the battery.
2. Raise the rear seat cushion.
3. Remove the fuel tank access cover.
4. Disconnect the connector (1) of the fuel pump/fuel level sensor unit.
5. Disconnect the fuel supply hose (2) (green connector).
6. Disconnect the fuel return hose (1) (red connector).
7. Using the Mot. 1397 key, loosen the nut (4) securing the unit, unscrew the nut by hand.
8. Carefully remove the fuel pump/fuel level sensor assembly.
Note: If a pause of several hours is expected between removal and installation of the unit, install the unit fastening nut in place to avoid deformation of the seat.
Installation
1. Replace the fuel pump/fuel level sensor assembly seal.
2. Install the unit so that the arrow (F) is opposite the middle mark (P) on the top of the tank.
3. Screw on the fastening nut (4) by hand and tighten it with a wrench so that the mark (D) is opposite the middle mark (P) and mark (F).
4. Reinstall the removed parts.
Table: Fuel Pump/Fuel Level Sensor Assembly Pin Description
| Conclusion | Purpose |
| A1 | "earth" |
| A2 | not used |
| B1 | fuel level sensor signal |
| B2 | not used |
| C1 | fuel pump supply (positive) |
| C2 | fuel pump supply (minus) |
Table. Fuel pump characteristics
| Type | Pressure | Innings |
| For a contour with return | 3±0.06 bar | 80 l/h |
| For a contour without return | 3.5 bar | 160 l/h |
Table. Fuel level sensor characteristics
| Resistance (Ohm) at terminals A1 and B1 | Fuel level | Float height (mm) |
| Less than 7 | 4/4 | Upper limiter |
| 55 ±7 | 3/4 | 142 |
| 98±10 | 1/2 | 111 |
| 115±15 | 1/4 | 89 |
| 280±20 | Turn on the indicator | 45,5 |
| 310±10 | Reserve | Bottom limiter |
Note: When checking, make sure that the resistance of the sensor changes continuously as the float height changes. The float height is measured from the sealing surface to the axis of the float pin. These tables are provided for reference.
Checking fuel consumption
1. Disconnect the fuel return hose (G) from the fuel pump/fuel level sensor assembly.
2. Insert the hose into a 2000 ml graduated cylinder.
3. Run the fuel pump for 30 seconds (either using a diagnostic tester or by installing a jumper on the fuel pump relay.
4. Calculate fuel consumption.
Nominal fuel consumption:
- For a circuit with return - 80 l/h
- For a circuit without return - 160 l/h