Suction Jet Pump, Removing, Installing, and Checking (AWD only)

(All Wheel Drive)

SUCTION JET PUMP, REMOVING AND INSTALLING, CHECKING


Function
In vehicles with All Wheel Drive (AWD), due to the construction style of the fuel tank, it is required to pump fuel from the area of the Fuel Level Sensor 2 -G169- to the fuel delivery unit using a suction jet pump. A second suction jet pump ensures the priming of the Fuel Pump (FP) in the baffle housing. The suction jet pumps operate according to the principle of fluid entrainment. They are propelled by the fuel return via a distribution piece with pressure relief valve.

Note: A test is only to be peiformed if the engine stops running due to lack of fuel, even though the fuel gauge indicates the fuel tank is 1/4 full.

Special tools, testers and auxiliary items required
- Release tool T40020

Conditions
- Fuel Level Sensor G OK
- Fuel Level Sensor 2 -G169- OK
- Fuel Supply Sensor 3 -G237- OK

Work sequence

- Remove Fuel Level Sensor 2 -G169-.
- Remove flange of Fuel Pump (FP) and distribution piece from baffle housing.






- Disconnect connector - 6 - from thermal switch.
- Pull distribution piece - 4 - as far as possible toward right.
- Remove return line - 7 - from distribution piece (press catch inward).
- Pull return line - 3 - out of baffle housing.
- Now suction jet pump can be pulled out from Fuel Level Sensor 2 -G169- side (left side of vehicle).
- Check that fuel hoses/lines on suction jet pump are installed securely and are not damaged.
- Additionally check suction jet pump for contamination/dirt if necessary.

If no malfunctions are found:

Note: In the following work procedure, the return line must be disconnected from the distribution piece. Ensure all 0-rings are replaced during this procedure.

Check the distribution piece with pressure relief valve as follows:






- Remove connection of return line - 1 - as well as connection - 2 - for suction jet pump at distribution piece with pressure relief valve - 4 - (disengage return line - 1 - using release tool T40020).
- Take an assisting hose and blow into connection from side of fuel return - 1 -.
- There must be throughput in direction - 2 - and - 7 -.
- If connections - 2 - and - 7 - are kept closed and then blown into, pressure relief valve must open due to generated pressure.

If no pressure can be noticed or the pressure relief valve does not open:

- Replace distribution piece with pressure relief valve.


Further installation:

- Install Fuel Pump (FP).
- Install Fuel Level Sensor 2 -G169-.