With Manufacturer's Scan Tool

Fuel Pump (FP) Relay -J17-, Checking And Activating

Special tools and equipment







- VAG1526A
- VAG1594A
- VAG1598/31
- VAS 5051 with VAS 5051/1

Voltage is supplied to the Fuel Pump (FP) and several components of the injection system via the Fuel Pump (FP) relay -J17-.

Engine must be turning for Fuel Pump (FP) relay -J17- to close, i.e. the relay does not receive Ground (GND) (via the Engine Control Module - ECM-) until the ECM recognizes RPM signals.

Test requirement:
- Battery voltage at least 12.7 V

Function test of Fuel Pump (FP) relay
- Remove driver-side storage compartment.
- Connect VAS5051 tester scan tool and select the control module for engine electronics using "address word" 01. Connecting VAS 5051/VAG 1551 Scan Tool (ST)
- Initiate output Diagnostic Test Mode and activate Evaporative Emission (EVAP) canister purge regulator valve -N80- (Tank Ventilation Valve). Output Diagnostic Test Mode (DTM), (Function 03)







- Fuel Pump (FP) relay (at position 4 of micro-central electronics in driver's footwell, left) must trigger and Fuel Pump (FP) must run.
- Exit function "03 - Output check diagnosis" by pressing <- button.

A If relay does not trigger:
- Check voltage supply for Fuel Pump (FP).
- Check activation of Fuel Pump (FP) relay.
B If relay triggers, but Fuel Pump (FP) does not run:
- Check voltage supply for Fuel Pump (FP) and components (via Fuel Pump -FP- relay).

Checking voltage supply for Fuel Pump (FP)
- Remove fuel pump relay.







- Connect multimeter to terminal 17 of relay socket and Ground (GND) for voltage measurement.
- Specification: approx. battery voltage

If specified value is not obtained:
- Replace the micro-central electronics.

Checking activation of Fuel Pump (FP) relay
- Turn off ignition.
- Connect VAG1598/31 test box at wiring harness to ECM, do not connect ECM. Electrical Testing Using VAG1598/31 Test Box
- Connect socket 65 and socket 1 of test box to each other using adapter cable from VAG1594A connector test kit.
- Switch ignition on.







- Fuel Pump (FP) relay (at position 4 of micro-central electrics in driver's footwell, left) must trigger.

If relay triggers now, but didn't during output DTM:
- Replace Engine Control Module (ECM).

If relay does not trigger:
- Switch ignition off.
- Remove adapter cable.
- Remove Fuel Pump (FP) relay.







- Connect multimeter to terminal 19 of relay socket and Ground (GND) for voltage measurement.

Micro-central electronics in Measure against
driver-side footwell, left,
position 4 Terminal
19 Engine ground

- Switch ignition on.
- Specification: approx. battery voltage

If specified value is not obtained:
- Check wire connections.

If specified value is obtained:
- Check the following wire connection for open circuit and short circuit to Ground (GND) and B+:

Micro-central electronics in VAG1598/31
driver-side, footwell, left, test box
position 4
Terminal Socket
16 65

- Repair open circuit or short circuit if necessary.

If no malfunctions are detected:
- Replace Fuel Pump (FP) relay -J17-.
- Re-connect Engine Control Module (ECM).

Check voltage supply for Fuel Pump (FP) and components







- Disconnect fuses S228, S232, S234 and S243 (positions 28, 32, 34 and 43) from fuse holder.
- Initiate output Diagnostic Test Mode (DTM) and activate Evaporative Emission (EVAP) canister purge regulator valve -N80-. Output Diagnostic Test Mode (DTM), (Function 03)
- Connect multimeter for voltage measurement to Ground (GND) and to one terminal of the following fuses in the fuse holder.

Fuse Specified value at one of the terminals
S228 approx. battery voltage
S232 approx. battery voltage
S234 approx. battery voltage
S243 approx. battery voltage

If specified values are not obtained:
- Repeat test at another terminal of fuse socket.

If specified values are not obtained again:
- Check wire connections.

If no malfunctions are detected:
- Replace Fuel Pump (FP) relay -J17-.
- Re-insert fuses.