Leak Detection Pump (LDP), Checking
Leak Detection Pump (LDP), Checking
Recommended special tools and equipment
- V.A.G 1526 multimeter or V.A.G 1715 multimeter
- V.A.G 1594 connector test kit
- Wiring diagram
Test requirements
- Corresponding fuses on E-box in engine compartment, left side, for Leak Detection Pump (LDP) -V144- must be OK
NOTE: Fuses on this fuse holder are labelled "SB" in the wiring diagram.
- Ground (GND) connections between engine and chassis must be OK.
- Ignition switched off.
Test sequence
Observe safety precautions.
Observe rules for cleanliness.
- Remove right rear wheelhousing liner.
- Disconnect 3-pin connector of Leak Detection Pump (LDP) -V144- (arrow).
Checking resistance
- Check resistance between terminals 1 and 3 of diagnostic pump.
Specified value: 640...720 ohms
- Check resistance between terminals 2 and 3 of diagnostic pump.
Specified value: 12.0...20.0 ohms
If specified values are not obtained:
- Replace Leak Detection Pump (LDP) -V144-.
- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 04 - Erase DTC Memory
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
If specified values are obtained:
- Check wires to Engine Control Module (ECM) according to wiring diagram.
Checking wires to Engine Control Module (ECM)
- Connect test box to 94-pin connector of wiring harness, connecting test box for wiring test.
Engine Control Module (ECM) is not connected.
- Check wires between test box and 3-pin connector to Engine Control Module (ECM) for open circuit according to wiring diagram.
Terminal 1 + socket 40
Terminal 2 + socket 8
Wire resistance: max. 3.0 ohms
- Also check wires for short circuit to each other, to vehicle Ground (GND) and to B+.
Specified value: infinity ohms
- Check wire between 3-pin connector terminal 3 and fuse holder for open circuit according to wiring diagram.
Wire resistance: max. 3.0 ohms
- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 04 - Erase DTC Memory
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes
If no malfunctions are found in wires:
Replace Engine Control Module (ECM) -J623-.