With Manufacturer's Scan Tool

Leak Detection Pump (LDP) -V144-, checking





Special tools and equipment
^ VAG1526 A Multimeter, or equivalent
^ VAG1527B Voltage tester
^ VAG1594 A or VW 1594 Adapter kit
^ VAG 1598/22 Adapter F/VAG 1598 (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 11.5 V minimum.

Test sequence
- Remove right rear wheel housing liner.





- Disconnect 3-pin harness connector from Leak Detection Pump (LDP) -V1 44- -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
=>Electrical Wiring Diagrams, Troubleshooting & Component Locations
^ 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 VAG1598/22 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 = 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:
Refer to Powertrain Management
- Readiness code must be reset if ECM is subject to low voltage with ignition ON or if DTC memory was erased.
Refer to Powertrain Management

Resistance testing
Test sequence
- Remove left rear wheel housing liner.





- Disconnect 3-pin harness connector from Leak Detection Pump (LDP) V1 44 -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:
Refer to Powertrain Management
- Readiness code must be reset if ECM is subject to low voltage with ignition ON or if DTC memory was erased.