With Generic Scan Tool

Leak Detection Pump (LDP), Checking

Recommended special tools and equipment
- V.A.G 1526 multimeter or V.A.G 1715 multimeter
- V.A.G 1594 connector test kit
- Wiring diagram

Requirements







- The respective fuses of Leak Detection Pump (LDP) -V144- must be OK.
- Fuel Pump (FP) relay -J17- must be OK, check.
- Ignition switched off.

Work sequence
- Remove right rear wheelhousing liner.







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







- Measure resistance between terminals 1 + 3 of leak detection pump.

Specified value: 640 to 720 Ohms

- Measure resistance between terminals 2 + 3 of leak detection pump.

Specified value: 12.5 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 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.

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, BBW, BEV







- 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

Continued for all vehicles
- 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-.