Activating Leak Detection Pump (LDP) V144 :

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2002 Volkswagen Jetta, 2002 Volkswagen GTI, 2001 Volkswagen Jetta, 2001 Volkswagen GTI, and 2000 Volkswagen Jetta. However, it is still accessible from the selected car via links, so may be relevant.

Press → button.

Indicated on display

Output Diagnostic Test Mode ->
Leak Detection Pump (LDP) V144

The fuel system Leak Detection Pump (LDP) V144 must click until the output DTM is terminated by pressing the → button.

If the diagnostic pump does not click:

Remove right rear wheel housing liner. → 66 EXTERIOR EQUIPMENT

Fig 1: Locating Connector Of Leak Detection Pump V144

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Disconnect 3-pin harness connector - arrow - from Leak Detection Pump (LDP) V144.

Fig 2: Voltage Tester VAG 1527B Connected To Disconnected Harness Connector Terminals

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Using adapter cables from VW 1594 , connect voltage tester VAG 1527B to disconnected harness connector terminals - 2 - and - 3 -.LED must flash (bright/darker)

If LED flashes:

Proceed with output DTM until completed.
Switch ignition off.
Replace fuel supply system Leak Detection Pump (LDP) V144. → 20 - FUEL SUPPLY
Check DTC memory. If necessary, repair any malfunctions and erase DTC memory → Diagnostic Trouble Code (DTC) memory, checking and erasing (scan tool functions 02 and 05) .

Display readiness code → Readiness code (function 15), displaying . If DTC memory has been erased, the readiness code must be generated again → Readiness code (function 15), generating .

If LED does not flash:

Proceed with output DTM until completed.
Switch ignition off.
Remove wiper arms and plenum chamber cover. → 92 WINDSHIELD WIPER & WASHER SYSTEM

Fig 3: Identifying Test Box V.A.G 1598/31 Connected To Control Module Wiring Harness

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Connect Test box VAG 1598/31 to control module wiring harness. The engine control module is not connected by this action.

Fig 4: Identifying 3-Pin Connector

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Check wiring for open circuit between test box and 3-pin harness connector using wiring diagram. Terminal - 1 - + socket 80. Terminal - 2 - + socket 25. Wire resistance: max. 1.5 Ω
Additionally, check wire for short circuit to battery positive (B+) and Ground. Specification: ∞ Ω

Fig 5: Identifying 3-Pin Connector

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Using wiring diagram, check wire between terminal 3 of relay plate and Fuel Pump (FP) relay J17 for open circuit. Wire resistance: max. 1.5 Ω

If no wiring malfunction is detected:

Replace Motronic ECM J220 → Engine Control Module (ECM), replacing .