Fuel Pump Control Module, FSI, Checking

Special tools and workshop equipment 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 .

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

• Remove rear seat bench. Refer to BENCH SEAT .
• Unbolt cover for right locking flange -arrows-.
  Fig 1: Right Locking Flange Bolts

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• 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.
Fig 2: Connecting Hand Multimeter V.A.G 1526C With Measuring Probes And Connector Adapters From Connector Test Set V.A.G 1594C Between Clamp
Courtesy of AUDI OF AMERICA, LLC

• 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 .
• Disconnect electrical harness connector -arrow- on fuel pump (FP) control module.
  Fig 3: Identifying Fuel Pump (FP) Control Module J538

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• Connect multimeter between terminal -3- and -4- of harness connector for voltage measurement.
Fig 4: Fuel Pump (FP) Control Module Terminals
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• 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.
  Fig 5: Connecting Multimeter With Measuring Probes And Connector Adapters From Connector Test Set V.A.G 1594 C Between Clamp

  Courtesy of AUDI OF AMERICA, LLC

• 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. Refer to the appropriate Fuel Injection and Ignition information.
  Fig 6: Adapter Cable V.A.G 1598/39 & Test Box V.A.G 1598/42

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

Harness Connector Terminal	-V.A.G 1598/42- Bushing
-5-	B 35

• 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 .