Operation CHARM: Car repair manuals for everyone.
Home >> Audi >> 1998 >> A4 Sedan (8D2) V6-2.8L (AHA) >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Testing and Inspection >> Component Tests and General Diagnostics >> Leak Detection Pump (LDP), Checking
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Leak Detection Pump (LDP), Checking




Leak Detection Pump (LDP), Checking

Electrical testing







- Disconnect harness connector for LDP -V144-
- Connect multimeter US1119 (Fluke 83 or equivalent) and check resistance at leak detection pump. Specified values:
- Connector terminal 1 to terminal 3: 640-720 Ohms
- Connector terminal 2 to terminal 3: 11.0-21.0 Ohms

If resistance is NOT OK:
- Replace leak detection pump -V144-.

Voltage supply, checking







- Disconnect harness connector for LDP -V144-.
- Connect VAG1527B LED voltage tester between connector terminal 3 (B+) and engine Ground.
- Start engine and run engine at idle. LED must light up.

If LED tester does not light:
- Check fuse for LDP -V144-.
- Check wiring for open circuit between terminal 3 and fuse, according to wiring diagram.
Specified value: max. 0.5 Ohm.
- Check fuel pump relay and signal to relay. Testing and Inspection
pro multis · About Operation CHARM