A4 Sedan L4-1.8L Turbo (AEB) (1997)
Leak Detection Pump: Component Tests and General Diagnostics
Leak Detection Pump (LDP), checking
Electrical testing
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Disconnect harness connector for LDP -V144-.
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Connect multimeter US 1119 (Fluke 83 or equivalent) and check resistance at leak detection pump. Specified values:
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Connector terminal 1 to terminal 3: 640 - 720 Ohms
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Connector terminal 2 to terminal 3: 17.5 - 27.5 Ohms
If resistance is NOT OK:
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Replace leak detection pump -V144-.
Voltage supply, checking
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Disconnect harness connector for LDP -V144-.
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Connect VAG 1527B LED voltage tester between connector terminal 3 (B+) and engine Ground.
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Start engine and run engine at idle.
LED must light up.
If LED tester does not light:
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Check fuse for LDP -V144-.
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Check wiring for open circuit between terminal 3 and fuse, according to wiring diagram. Specified value: max. 0.5 Ohms.
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Check fuel pump relay and signal to relay. See: Fuel Delivery and Air Induction/Fuel Pump/Fuel Pump Relay/Testing and Inspection