SEAT Workshop Service and Repair Manuals

Checking function and voltage supply Test prerequisites l  The battery voltage must be at least 11.5 V. l  Fuse for the fuel pump control unit -J538- in good condition. l  Fuel pump control unit -J538- in good condition Test sequence:   Note The operation of the fuel pump is checked with the actuator diagnosis.

–  Connect the vehicle diagnosis system as follows: –  Plug the connector 2 of the diagnosis cable into the diagnosis socket in the footwell on the driver's side. –  Switch on ignition. –  On the display, press the pushbuttons Vehicle self-diagnosis, Engine electronics and Actuator diagnosis one after another. –  Press the right-hand side button until the fuel pump electronic actuator diagnosis is selected. The fuel pump should start running, first slowly and then gradually up to full power.   Note The fuel pump runs very quietly. –  Switch off ignition. If the fuel pump does not run: –  Fold down the rear seat forwards.

–  Disconnect the connector of the fuel pump control unit -J538-.

–  Using the multimeter -V.A.G 1715-, check the supply voltage between contacts -1- and -6-. l  Specification: approx. battery voltage. Power supply is not okay: –  Locate and rectify open circuit using current flow diagram → Current flow diagrams, Electrical fault finding and Fitting locations.

Power supply is okay: –  Remove the cover -1- of the fuel delivery unit together with the fuel pump control unit -J538--2-.

–  First check that connector -1- is fitted securely by pulling connector without pressing catch. If the plug connector had not been connected properly, the functional inspection of the fuel pump must be repeated. –  Now pull off connector. –  Check the contact on the plug connector and the fuel supply unit for damage.   WARNING Fuel supply line is pressurised. Wear eye protection and protective clothing to avoid possible injury and skin contact. Before loosening hose connections, wrap a cloth around the connection. Then release pressure by carefully pulling hose off connection. –  Disconnect the fuel lines -1- and -2- from the flange.   Note Press in securing ring to release fuel lines.

–  Open locking ring using union nut tool -3217-. –  Check that electrical wires between flange and fuel pump are connected. If no open circuit can be found: –  Fuel pump is defective, renew fuel delivery unit → Chapter.