Leak Detection Pump (LDP), Check

Leak Detection Pump (LDP) -V144-, 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

Test requirements







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

Test sequence
- Remove wheel housing liner, rear left.







- Disconnect 3-pin connector of 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 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 AHA







- Check wires between test box and 3-pin connector for open circuit according to wiring diagram.
Terminal 1 + socket 37
Terminal 2 + socket 16
Wire resistance: max. 1.5 ohms

Vehicles with engine code ATQ







- Check wires between test box and 3-pin connector for open circuit 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 ohm
- 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-.