Fuel Pump (FP) check-valve, checking

Test conditions

Remote control V.A.G 1348/3A connected
Fuel Inj. Pressure Gauge V.A.G 1318 is still connected.

Test sequence

NOTE:

This test also checks the connections of the fuel supply line from fuel delivery unit to connection point of pressure gauge V.A.G 1318 for proper seal.

Fig 1: Pressure Gauge V.A.G 1318 Connections

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Close pressure gauge V.A.G 1318 shut-off tap (lever at right angle to direction of flow position - B - ).
Operate remote control at short intervals, until a pressure of approx. 3 bar has built up.

CAUTION: Danger of spraying when opening shut-off valve; wear protective goggles and protective clothing to prevent injuries and contact with skin. Hold container in front of free connection of pressure measuring device V.A.G 1318.

If pressure builds up too high, lower excess pressure by carefully opening shut-off tap.
Watch pressure drop on gauge. After 10 minutes the pressure must not drop below a 2.5 bar decrease.

If pressure drops further:

Check line connections for leaks.

If no fault is detected in wiring:

Fuel Pump (FP) faulty, replace fuel delivery unit refer to Fuel delivery unit, removing and installing .
Check DTC memory.
Read readiness code.
If DTC memory was cleared or engine control module disconnected from voltage supply, readiness code must be regenerated.