Transfer Fuel Pump, Checking

NOTE:

Models with an airbag are installed with a crash fuel shut-off system. It reduces the danger of a fire in a crash as the fuel pump is switched off via the fuel pump relay.
When the door is opened the fuel pump is activated for 2 seconds to build up the pressure in the fuel system.

Special tools and workshop equipment required

Test conditions

Test procedure

-- Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK .

Test sequence

-- Remove the rear seat bench. Refer to the appropriate service information.

-- Remove cover retainers from the right sealing flange.

-- Disconnect the electrical harness connector from the Transfer Fuel Pump (FP) -G6- fuel delivery unit.

-- Connect a hand-held remote control (jumper) to terminal 5 of the fuel delivery unit and to vehicle battery (+).

-- Connect a jumper cable from an Electrical connector test lead set to terminal 1 of the fuel delivery unit and to vehicle Ground (GND).

Fig 1: A Jumper Cable From A Electrical Connector Test Lead Set Connected To Terminal Of Fuel Delivery Unit And To Vehicle Ground

Courtesy of AUDI OF AMERICA, LLC

-- Press switch on the hand-held remote control (jumper).

NOTE:

The Fuel Pump (FP) runs quietly. Avoid surrounding noises while testing the fuel pump.

-- Listen for an operating noise from the fuel pump.

If no operating noise is heard:

-- Remove the fuel delivery unit.

-- Using a multimeter, check the electrical circuit between terminals 1 to and 5 of the fuel delivery unit pump motor for resistance.

Fig 2: Checking Electrical Circuit Between Terminals And Of Fuel Delivery Unit For Resistance

Courtesy of AUDI OF AMERICA, LLC

Specified value: 1.5 Ω max.

If the specification was not obtained:

-- Check the wiring for an open circuit, a short circuit to Battery positive (+) or to Ground (GND).

-- Check the electrical harness connector for damage, corrosion, loose or broken terminals.

-- If necessary, repair the wiring connection.

If the specification was obtained:

-- Replace the fuel delivery unit.

Final procedures

After repair work, the following work steps must be performed in the following sequence:

Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .