With Manufacturer's Scan Tool

Leak Detection Pump (LDP) -V144-, checking

Special tools and equipment





^ VAG 1715 Multimeter
^ VAG 1527 B LED test light
^ VAG 1594 A Adapter set
^ VAG 1598/22 Test box
^ Wiring diagram

Checking voltage supply

Test conditions





- Fuse No. 43 must be OK
- The battery voltage must be at least 11.5 V

Test sequence
- Remove rear right wheel well liner.






- Disconnect 3 pin connector from Leak Detection Pump -V144-.






- Connect LED test light VAG 1527 between connector terminal 3 (positive) and engine Ground.
- Start engine and run at idling speed:
LED must light up.

- Switch ignition off.

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

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






- Connect test box VAG 1598/31 to control module wiring harness. Engine Control Module is not connected by this action.






- Check wiring between test box and 3 pin connector for open circuit using wiring diagram.

Contact 1 + socket 80
Contact 2 + socket 25
Wire resistance: Max. 1.5 ohms

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

If no wiring malfunction is detected and voltage was present between contact 3 and Ground:
- Replace Leak Detection Pump -V144.
- Check DTC memory.
- Read readiness code.

If the DTC memory has been erased or the engine control module separated from permanent positive, the readiness code must be generated again.






- Check wiring between test box and 3 pin connector for open circuit using wiring diagram.
Contact 1 + socket 80
Contact 2 + socket 25
Wire resistance: Max. 1.5 ohms

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

- If no wiring malfunction is detected and voltage was present between contacts 1 + 3:
- Replace Leak Detection Pump -V144-.
- Check DTC memory.
- Read readiness code.

If the DTC memory has been erased or the Engine Control Module separated from permanent positive, the readiness code must be generated again.

Checking resistance

Test sequence
- Remove rear right wheel housing liner.






- Disconnect 3-pin connector from Leak Detection Pump -V144-.






- Connect hand multimeter VAG1526 to measure resistance between contacts 1 and 3 of -V144
Specification: 640-720 ohms

- Connect hand multimeter VAG1526 to measure resistance between contacts 2 and 3 of -V144 a specification of 17.5-27.5 ohms
Specification: 12.5 to 19.5 ohms

If the specifications are not attained:
- Replace Leak Detection Pump -V144-.
- Check DTC memory.
- Read readiness code.

If the DTC memory has been erased or the Engine Control Module separated from permanent (battery) positive, the readiness code must be generated again.