Transfer Pump Fuel Volume Check
- Turn ignition off. To check transfer pump (in tank), remove rear seat. Remove fuel sending unit access cover. Disconnect ignition coil secondary wire and connect to ground.
- With transmission in Neutral, crank engine for 3-4 seconds. While starter is turning and for a few seconds afterward, an audible sound should be heard at the pump. If sound is not heard, go to next step. If sound is heard, go to step 5).
- Remove fuel pump relay from relay panel. On Corrado SLC and Passat, activate fuel pumps using Remote Control (VAG 1348/3A). On all others, activate fuel pumps using Remote Control (US 4480/3). On all models, if pump does not operate, remove transfer pump wire harness connector. See Fig 1
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- Using test light, check voltage between middle wire and outer Brown wire of fuel pump connector (Digifant system) or between Brown wire and Red/Yellow wire (Motronic system). If voltage is present, replace transfer pump. If voltage is not present, repair open or short circuit in wiring.
- Remove fuel pump relay jumper wire. Disconnect and plug transfer pump output hose. Attach a hose to pump outlet connector, and place other end of hose in a graduated container. Activate fuel pump for 10 seconds.
- Minimum fuel flow should be 10 ounces (.3 liter). If fuel flow is low, check fuel tank filter for restriction. If fuel tank filter is okay, replace transfer pump.
Courtesy of VOLKSWAGEN UNITED STATES, INC.