With Generic Scan Tool

Leak Detection Pump (LDP), checking

Recommended special tools and equipment
- V.A.G1526 multimeter or V.A.G1715 multimeter
- V.A.G1594 connector test kit
- Wiring diagram

Test requirements






- The respective fuses of Leak detection pump (LDP) -V144- must be OK.
- Ignition switched off.

Test sequence

- Remove wheelhousing liner, rear left.






- Disconnect 3-pin connector Leak detection pump (LDP) -V144- (arrow).






- Measure resistance between terminals 1 + 3 of diagnostic pump.
Specified value: 640 to 720 Ohms.

- Measure resistance between terminals 2 + 3 of diagnostic pump.
Specified value: 17.5 to 19.5 Ohms.

If specified values are not obtained:

- Replace Leak detection pump (LDP) -V144-.

- Erase DTC memory of Engine Control Module (ECM). Diagnostic Mode 04: Reset/Delete Diagnostic Data

- Generate readiness code.

If specified values are obtained:

- Connect test box to control module wiring harness.






- Check wires between test box and 3-pin connector for open circuits according to wiring diagram.

Terminal 1 + socket 37
Terminal 2 + socket 16
Wire resistance: max: 1.5 Ohms

- Check wires for short circuits to each other, to vehicle Ground (GND) and to B+.
Specified value: Infinity Ohms

- Check wire between 3-pin connector terminal 3 and the Fuel Pump (FP) Relay -J17- for open circuit according to wiring diagram.
Wire resistance: max: 1.5 Ohms

If no malfunctions are found in wires:

- Replace Motronic Engine Control Module (ECM) -J220-.