Fuel Pump: Testing and Inspection
Fuel Pump Checking;- Wiring diagram
- Measuring cylinder
- Battery Voltage must be OK
- Fuse Sl8 must be OK
- Switch on ignition
Fuel pump must run briefly (listen for it). If pump does not run, Switch off ignition
- Remove cover from fuse relay panel.
- Remove fuel pump relay (J17) form fuse/relay position 12
Note:
Get radio theft code first before disconnecting the battery.
- Disconnect battery ground strap first if tools are necessary to
remove relays or control modules from the fuse/relay panel.
- Connect remote VAG 1348/3A with adapter wire VAG 1348/3-2 to connector 4 and battery plus (+).
- Operate remote.
If pump runs:
- Install fuel pump relay again.
- Check activation of fuel pump relay with applicable wiring diagram and tester VAG 1598/18.
If pump does not run:
- Remove luggage compartment floor cover
- Disconnect 4-pin connector at fuel pump flange.
If pump runs:
- Install fuel pump relay again.
- Check activation of fuel pump relay with applicable wiring diagram and tester VAG 1598/18.
If pump does not run:
- Remove luggage compartment floor cover
- Disconnect 4-pin connector at fuel pump flange.
- Connect LED tester VAG 1527B to outer terminals of connector using jumper wires from test kit VAG 1594.
- Operate remote control. LED must light up
If LED does not light up:
- Check wiring using applicable wiring diagram and Component Locations.
LED lights up:
- Loosen flange nut using tool 3217
- Check whether wiring is properly connected between flange and fuel pump assembly
If no open circuit can be found:
- Replace fuel pump
Delivery rate, checking
- Voltage supply OK
- Remote control VAG 1 348/3A connected
- Remove fuel filler cap.
- Remove fuel supply line -1- from fuel rail.
CAUTION!
Danger of fuel spray when opening the tester shut-off. Hold container or lint-free rag over open connection.
- Connect pressure gage VAG 1318 using adapter 1318/10 to fuel supply hose -1-.
- Connect hose VAG 131811 to adapter VAG 1318111 of the pressure gauge and point into measuring cylinder.
- Open pressure gauge shut-off lever (lever in flow position -A-).
- Operate remote control VAG 1348/3A and slowly close shut-off lever until gauge shows 4 bar. Leave shut-off lever in this position.
- Empty measuring cylinder.
- Operate remote control for 30 seconds.
- Compare amount of fuel delivered with chart.
*) Minimum fuel delivered in 30 sec.
**) Voltage at pump when engine is not running but pump running approx. 2 V less than battery voltage.
If you have less fuel than the minimum delivery rate:
- Check for blocked or kinked fuel lines.
- If fuel filter is blocked, replace
- If fuel pump is faulty, replace