Fuel Pump Control Module, FSI, Checking

Fuel Pump Control Module, FSI, Checking

Special tools, testers and auxiliary items required

• Hand-held multimeter (V.A.G 1526C)

• Connector test set (V.A.G 1594C)

• Adapter cable (V.A.G 1598/39)

• Test box (V.A.G 1598/42)

Procedure

Observe test conditions. Refer to => [ Test Conditions ] Test Conditions.

Check voltage supply for Fuel Pump (FP) (from Fuel Pump (FP) Control Module (J538))

- Remove rear seat bench.





- Unbolt cover for right locking flange - arrows -.

- For voltage testing, connect the (V.A.G 1526C) with measuring probes and connector adapters from the (V.A.G 1594C) between clamp - 1 - and - 5 -, as shown in the illustration. The electrical connection remains connected.





• Connector sockets are numbered respectively on the rear side of the connector.

- Start engine.

• Specified value at start and in idle: 4 to 5 V.

- Depress accelerator pedal completely and then release it (brief throttle burst).

• Specified value: The voltage value must first rise slightly, then fall and then rise again to the value previously read.

If the reading does not result as described:

- Check voltage supply and activation of the Fuel Pump (FP) Control Module.

Check voltage supply for Fuel Pump (FP) Control Module





- Remove fuel pump (FP) control module. Refer to => [ Fuel Pump Control Module ] Fuel Pump Control Module.

- Disconnect electrical harness connector - arrow - on fuel pump (FP) control module.

- Connect multimeter between terminal - 3 - and - 4 - of harness connector for voltage measurement.





- Switch on ignition.

• Specified value: approximately battery voltage.

If the specification is not obtained:

- Repair open circuit in wiring according to wiring diagram.

Check activation of Fuel Pump (FP) Control Module





- Remove protective cap.

- For voltage testing, connect the multimeter with measuring probes and connector adapters from the (V.A.G 1594C) between clamp - 4 - and - 5 -, as shown in the illustration. The electrical connection remains connected.

• Connector sockets are numbered respectively on the rear side of the connector.

- Start engine.

• Specified value at start and in idle: approximately 5.0 V

- Depress accelerator pedal completely and then release it (brief throttle burst).

• Specified value: The voltage value must first rise slightly, then fall and then rise again to the value previously read.

If the reading does not result as described:





- Switch off ignition.

- Connect (V.A.G 1598/42) to wiring harness with (V.A.G 1598/39-1) or (V.A.G 1598/39-2); engine control module (ECM) is not connected. Clamp test box ground (GND) clip to battery negative terminal.

CAUTION!
Risk of destroying electrical components.

• Before connecting the test leads, switch on the respective measuring range and observe the test conditions.

- Check the following wire connection for open circuit and short circuit to ground (GND) and B+:









- Repair wiring open circuit or short circuit according to wiring diagram.

If no malfunctions are detected:

- Replace the fuel pump (FP) control module. Refer to => [ Fuel Pump Control Module ] Fuel Pump Control Module.