Audi Workshop Service and Repair Manuals

Removing and installing fuel pump control unit -J538- Removing Observe safety precautions → Chapter. Observe rules for cleanliness → Chapter. l  Fuel tank must be empty when lowering it to reduce weight. Drain the tank if necessary. Procedure → Chapter.

Caution Observe notes on procedure for disconnecting the battery → Rep. Gr.27. –  Slide cover above battery to the right -arrow 1- and lift off -arrow 2-.

–  With ignition switched off, disconnect earth strap -arrow- at battery.

Audi RS4: –  Lift luggage compartment floor mat and make sure it remains in position. –  With ignition switched off, disconnect earth strap -arrow- at battery.

All models: –  Open tank flap and detach loop -1- on tank flap.   Note Do not remove filler cap. –  Clean area around fuel filler neck. –  Lever off retaining ring -arrow- in rubber cup and press rubber cup through to inside.

–  Remove rear wheel (right-side). –  Remove rear right wheel housing liner → Rep. Gr.66. –  Disconnect breather pipe -3- from fuel filler neck.   Note Disregard -item 2-. –  Unscrew bolt -1- for fuel filler neck.

–  Remove cover -1- from underside of vehicle (rear right).   WARNING To reduce weight, fuel tank must be empty when lowering it.

–  Loosen bolts -1 ... 5-, -9- and -10- by turning not more than 8 turns. –  Unscrew bolts -6-, -7- and -8-.

–  Remove rear seat bench → Rep. Gr.72. –  Unscrew cover for flange (right-side) -arrows-.

Audi RS4: –  Move electrical connector -arrow- for fuel pump control unit -J538- clear and detach connector.

All models: –  Unplug electrical connector -arrow- at flange (right side of vehicle).

–  Mark fuel return pipe -1- and fuel supply pipe -2-.   WARNING The fuel system is pressurised. Before opening the system place a clean cloth around the connection. Then release pressure by carefully loosening the connection. –  Detach both pipes from flange (press release tabs). –  On vehicles with auxiliary heater, also disconnect fuel line leading to metering pump for auxiliary heater (press release tab).

–  Remove bolts -arrows-. –  Remove fuel pump control unit -J538-.

Installing Installation is carried out in the reverse order; note the following: –  Tighten bolts for securing straps and support bracket -1 ... 10-.

–  Secure fuel filler neck with earth connection using bolt -1-.   Caution After installation, use an ohmmeter to check the electrical connection between the metal ring on the fuel filler neck and a bare metal part on the body: Specification: approx. 0 Ω. –  Secure breather pipe -3- to fuel filler neck.   Note Disregard -item 2-. –  Install rear right wheel housing liner → Rep. Gr.66. –  Install rear seat bench → Rep. Gr.72. –  Connect battery. Observe notes on procedures required after connecting battery → Rep. Gr.27. Tightening torques

Component	Nm
Securing straps and support bracket for fuel tank to body	23
Fuel filler neck to wheel housing	23
Fuel pump control unit -J538- to underbody	2.5