With Manufacturer's Scan Tool

Leak Detection Pump (LDP) V144, Checking


Special tools and equipment







- VAG1526A Multimeter, or equivalent
- VAG1527B Voltage tester
- VAG1594A or VW 1594 Adapter kit
- VAG 1598/22 Adapter F/VAG1598 (68 PIN)
- VAG1598/31 Adapter cable (121-point)
- Wiring Diagram

Leak Detection Pump (LDP) V144 Voltage Supply, Checking

Test conditions







- All fuses must be OK.
- Battery voltage 11.5V minimum.

Test sequence
- Remove right rear wheel housing liner:







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







- Connect VAG1527 B Voltage Tester between connector terminal 3 (Battery Plus) and engine Ground.
- Start engine and run at idling speed
- LED must light up.
- Switch ignition off.

If LED does not light up
- Check wire for open circuit between connector terminal 3 and relay panel using wiring diagram
- Wire resistance: max. 1.5 Ohms

If LED lights (supply voltage OK):
- Remove inner plenum chamber cover, left.


Only Engine Code AEG:







- Connect test box VAG 1598/22 to ECM wiring harness.

Engine Codes AVH, AZG:







- Connect test box VAG1598/31 to control module wiring harness. The engine control module is not connected by this action.







- Check wiring for open circuit between test box and 3-pin harness connector using wiring diagram.
Only engine code AEG:
Contact 1 + socket 37
Contact 2 + socket 16
Engine codes AVH, AZG:
Contact 1 + socket 80
Contact 2 + socket 25
- Resistance: max. 1.5 Ohms

- Additionally check wires for short to one another.
- Specification: Infinity Ohms

If no wiring malfunction is detected and voltage was present between contact 3 and ground is OK:
- Replace Leak Detection Pump (LDP) V144.
- Read out Readiness code:
- Readiness code must be reset if ECM is subject to low voltage with ignition ON or if DTC memory was erased.

Resistance testing

Test sequence
- Remove left rear wheel housing liner







- Disconnect 3-pin harness connector from Leak Detection Pump (LDP) V144 -arrow-.
- Set hand multimeter VAG1526 to measure resistance.







- Connect hand multimeter VAG1526 to measure resistance between terminals 1 and 3 of Leak Detection Pump -V144- and measure resistance.
- Specification: 640...720 Ohms
- Connect hand multimeter VAG1526 to measure resistance between terminals 2 and 3 of Leak Detection Pump -V144- and measure resistance.
- Specification: 12.5...19.5 Ohms

If specifications are not obtained:
- Replace Leak Detection Pump (LDP) -V144-.
- Read out Readiness code:
- Readiness code must be reset if ECM is subject to low voltage with ignition ON or if DTC memory was erased.