With Manufacturer's Scan Tool

Leak Detection Pump (LDP), checking

Special tools and equipment
- Fluke 83 multimeter
- VAG 1527B voltage tester
- VW1 594 connector test kit
- Wiring diagram

Electrically checking leak detection pump






- Disconnect 3-pin harness connector of leak detection pump -V144-.
- Connect Fluke 838 multimeter to measure resistance between terminal -1- and -3- of -V144-.
Specification: 640 - 720 Ohms
- Connect Fluke 838 multimeter to measure resistance between terminals -2- and -3- of -V144-.
Specification: 17.5 - 27.5 Ohms

If the specifications are not attained:
- Replace leak detection pump -V144-.


Checking voltage supply

Test conditions



- Fuse 29 OK.

Test sequence




- Disconnect 3-pin harness connector of leak detection pump -V144-.
- Connect VAG 1527B voltage tester between connector contact 3 (positive) and engine Ground (GND).
- Start engine and run at idling speed:
LED must light up.

If the LED does not light up:
- Check wire between connector terminal -3- and relay panel for open circuit using wiring diagram