With Generic Scan Tool

Check Leak Detection Pump (LDP)

Recommended special tools and equipment
- VAG1526 multimeter or VAG1715 multimeter
- VAG1594 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 rear right wheelhouse liner.






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






- Measure resistance between terminals 1 + 3 of diagnostic pump. Specified value: 640 ... 720 Ohms
- Measure resistance between terminals 2 + 3 of diagnostic pump. Specified value: 12,5 ... 19,5 Ohms

If specified values are not obtained:
- Replace Leak Detection Pump (LDP) -V144-, item 8
- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes

If specified values are obtained:
- Connect test box to control module wiring harness, connect test box for wiring test. Test Box, Connecting For Wiring Test

Vehicles with engine code AEG







- 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

Vehicles with engine code AVH, AZG







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

Terminal 1 + socket 80
Terminal 2 + socket 25

Wire resistance: max: 1.5 Ohms

Continuation for all vehicles
- Also check wires for short circuit to each other, to vehicle Ground (GND) and to B+. Specified value: Infinite 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-.