With Manufacturer's Scan Tool
Leak Detection Pump (LDP), Checking
Special tools and equipment
- V.A.G 1526 A Hand multimeter
- VAG 1527B voltage tester
- V.A.G 1594 A Adapter set
- V.A.G 1598/31 Test box
- Wiring diagram
Electrically checking LDP
- Remove rear right wheel housing liner:
- Pull 3 pin connector off LDP -V144-.
- Connect hand multimeter V.A.G 1526 A to measure resistance between contacts 1 and 3 of LDP -V144-.
Specification: 640...720 Ohms
- Connect hand multimeter V.A.G 1526 to measure resistance between contacts 2 and 3 of LDP -V144-
Specification: 12.5...19.5 Ohms
If the specifications are not attained:
- Replace Leak Detection Pump (LDP) -V144-.
- Check DTC memory:
- Generate readiness code again if DTC memory has been erased or engine control module separated from permanent positive.
Checking voltage supply
Test conditions
- Fuse No. 43 must be OK.
- The battery voltage must be at least 11.5 V.
- Test sequence
- Disconnect 3 pin connector of LDP -V144-.
- Connect VAG 1527B voltage tester 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:
- Switch ignition off.
- Check wire between connector contact 3 and central electrics for open circuit using wiring diagram:
Wire resistance: max. 1.5 Ohms
LED lights up (voltage supply OK).
- Connect test box V.A.G 1598/31 to control module wiring harness. Engine control module remains disconnected.
- 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 3 and Ground:
- Replace Leak Detection Pump (LDP) -V144-.
- Check DTC memory
- Read readiness code
- Generate readiness code again if DTC memory has been erased or engine control module separated from permanent positive.