(LDP) V144 , Checking

Leak Detection Pump (LDP) -V144-, Checking







Recommended special tools and equipment
- VAG1526A multimeter
- VAG1594A connector test kit
- VAG1598/31 test box

Test requirements:
- Fuse for Leak Detection Pump (LDP) -V144- OK
- Fuel Pump (FP) Relay OK; checking. Testing and Inspection
- Ignition switched off.

NOTE: Voltage is supplied to Leak detection pump (LDP) -V144- via the Fuel Pump (FP) relay.

Work procedure
- Remove left rear wheel.
- Remove left rear wheel housing liner.







- Release and disconnect harness connector -3-.

Checking internal resistance







- Connect multimeter for resistance measurement as follows.

Leak Detection Pump (LDP) Specified
-V144- Terminal value
1 + 3 640 to 720 Ohms
2 + 3 15 to 17 Ohms

If specified values are not obtained:
- Replace Leak Detection Pump (LDP) -V144-.

If specified values are obtained:

Checking voltage supply







- Connect multimeter for voltage measurement as follows:

Harness connector Terminal Measure to
3 Engine Ground (GND)

- Operate starter briefly.
- Specified value: approx. battery voltage
- Switch ignition off.

If specified value is not obtained:
- Check wire connection from harness connector terminal 3 to Fuel Pump (FP) Relay - J17- via fuse for open circuit according to wiring diagram.
- Specified value: Wire resistance max 1.5 Ohms
- If necessary, repair wire connection.

If voltage supply is OK:

Checking wire connections
- Connect test box to wiring harness of Engine Control Module (ECM); ECM is not connected.







- Check the following wire connections for open circuit according to wiring diagram:
Harness connector Terminal Test box Socket
1 80
2 25

- Specified value: Wire resistance max 1.5 Ohms
- Check wires for short circuit to each other as well as to B+ and Ground (GND).

- Specified value: Infinity ohm (no continuity)

- If necessary, repair wire connection.

If no malfunctions are found in wires:
- Replace Engine Control Module (ECM).

Final procedures
After repair work, the following work steps must be performed in the mentioned sequence:
1. Check DTC memory. Diagnostic Mode 03 - Read DTC Memory
2. If necessary, erase DTC memory. Diagnostic Mode 04 - Erase DTC Memory
3. If DTC memory was erased, generate readiness code.

- End diagnosis and switch ignition off.