Leak Detection Pump (LDP), Checking

Leak Detection Pump (LDP), Checking

Special tools and equipment
- Multimeter VAG 1526 or Fluke 83
- Voltage tester VAG 1527B
- Adapter set VAG 1594
- Wiring diagram


Electrically checking LDP







- Disconnect 3-pin connector from LDP -V144-.
- Connect multimeter to measure resistance between contacts 1 and 3 of -V144-.
- Specification: 640 to 720 Ohms
- Connect multimeter to measure resistance between contacts 2 and 3 of -V144-.
- Specification for engine code AEB: 17.5 to 27.5 Ohms
- Specification for engine code ATW: 15.0 to 17.0 Ohms

If the specifications are not attained:
- Replace Leak Detection Pump -V144-.

Checking voltage supply

Conditions

Engine code AEB







- Fuse 29 must be OK

Engine code ATW

- Fuse 34 must be OK

Checking sequence







- Disconnect 3-pin connector from Leak Detection Pump (LDP) -V144-.
- Connect voltage tester VAG 1527B between connector contact 3 (positive) and engine Ground.
- Start engine and run at idling speed: LED must light up.

If the LED does not light up:
- Check wire between connector contact 3 and central electric for open circuit using wiring diagram, repair as necessary.