With Generic Scan Tool

Leak Detection Pump (LDP), Checking

Recommended special tools and equipment
- VAG1526 multimeter or VAG1715 multimeter
- VAG1594 connector test kit
- Wiring diagram

Test requirements







- The respective fuses of Leak detection pump (LDP) -V144- must be OK.
- Ignition switched off.

Test sequence
- Remove wheelhouse liner, rear left.







- Disconnect 3-pin connector of Leak detection pump (LDP) -V144- (arrow).







- Measure resistance between terminals 1 & 3 of diagnostic pump. Specified value: 640...720 Ohm
- Measure resistance between terminals 2 & 3 of diagnostic pump. Specified value: 17.5...19.5 Ohm

If specified values are not obtained:
- Replace Leak detection pump (LDP) -V144-, item 8
- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Readiness Code, Generating

If specified values are obtained:
- Connect test box to control module wiring harness, connect test box for wiring test. Test Box, Connecting For Wiring Test







- Check wires between test box and 3-pin connector for open circuits according to wiring diagram.
Terminal 1 & socket 80
Terminal 2 & socket 25
Wire resistance: max: 1.5 Ohm
- Also check wires for short circuits to each other, to vehicle Ground (GND) and to B+.
Specified value: Infinite Ohm
- Check wire between 3-pin connector terminal 3 and the Fuel Pump (FP) Relay -J17- for open circuit according to wiring diagram.
Wire resistance: max: 1.5 Ohm

If no wiring faults are found:
- Replace Motronic Engine Control Module (ECM) -J220-.