SEAT Workshop Service and Repair Manuals

Fuel pump control unit -J538-: check excitation

Special tools and workshop equipment required

t	Hand-held multimeter -VAG 1526B-

t	Auxiliary cable kit -VAG 1594C-

t	Adapter -VAG 1598/39-

t	Test box -VAG 1598/42-

Test conditions l  Battery voltage at least 12.5 V

l  Fuses -4- and -43- in the fuse holder, below the instrument panel, left-hand side, in good condition. Checking sequence –  Remove rear right seat → general body repairs, interior; Rep. gr.72. –  Lift carpet under the seats and fold backwards.

–  Release retainers -arrows- at cover for sealing flange.

–  To check voltage, connect the multimeter with measurement needles and connectable adapters from theauxiliary measurement kit -VAG 1594C- between contacts -2- and -6-, as shown in the illustration. The connector remains connected. –  Then start engine. l  Specified value when starting and when idling: Approx. 6.0 Volt. –  Depress the accelerator pedal completely and quickly and release (short kick to the accelerator). l  Specification: The voltage reading should rise at first, then fall and finally increase to the previous reading. If the reading is not as described:

–  Connect the test box -V.A.G 1598/42- with adapter cable -V.A.G 1598/39-2- to the 94-contact connector from the wiring harness; do not connect the engine control unit.   WARNING Before connecting the measuring cables, select the appropriate measurement field and follow the test procedures to avoid damaging electronic components.

–  Check for breaks, shorts to earth or battery positive in the following wiring connection:

Connector Contact	Test box -V.A.G 1598/42- Socket
-2-	48

–  Repair the cable break or short-circuit according to the circuit diagram. If no fault is found: –  Replace the fuel pump control unit -J538-.