With Manufacturer's Scan Tool

Leak Detection Pump (LDP) -V144-, Checking

Special tools





- VAG 1526 A Multimeter, or equivalent
- VAG 1527 B Voltage tester
- VAG 1594 A or VW 1594 Adaptor kit
- VAG 1598/22 Test box for engine code AEG
- VAG 1598/31 Test box for engine code AVH, AZG (not shown)
- 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) -V144- (arrow).






- Connect VAG 1527 B Voltage Tester between connector terminal 3 (Battery Plus) and engine Ground.
- Start engine and let idle
- LED must light up.

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

If LED lights (supply voltage OK):
- Remove wiper arms and cowl panel:

Engine code AEG:






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

Engine codes AVH, AZG:






- Connect test box VAG 1598/31 to ECM wiring harness.






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

Engine codes AVH, AZG:
Contact 1 + socket 80
Contact 2 + socket 25
Resistance: max. 1.5 Ohms

- Check wires for short to one another or ground
Specification: Infinity Ohms

If no fault in wiring is found and voltage between contact 3 and ground is OK:
- Replace Leak Detection Pump (LDP) -V144- (item 8)
- Display Readiness code Monitors, Trips, Drive Cycles and Readiness Codes
- Readiness code must be reset if ECM is subject to low voltage with ignition ON or if DTC memory is erased.

Resistance testing

Test sequence
- Remove right rear wheel housing liner:






- Disconnect 3-pin harness connector from Leak Detection Pump (LDP) -V144- (arrow).
- Switch Fluke 83 multimeter to resistance range.
- Connect Fluke 83 multimeter between terminals 1 and 3 of Leak Detection Pump -V144- and measure resistance.
Specification: 640 to 720 Ohms






- Connect Fluke 83 multimeter between terminals 2 and 3 of Leak Detection Pump -V144- and measure resistance.
Specification: 12.5 to 19.5 Ohms

If specifications not obtained:
- Replace Leak Detection Pump (LDP) -V144- (item 8 )
- Display Readiness code Monitors, Trips, Drive Cycles and Readiness Codes
- Readiness code must be reset if ECM is subject to low voltage with ignition ON or if DTC memory is erased.