EVAP Leak Detection Pump

A small electric pump that pressurises the evaporative system with air so the module can find leaks down to about half a millimetre — a hole far too small to detect any other way. Unusual in that it works while the vehicle is parked, typically some hours after shutdown when fuel has stopped sloshing and temperatures have settled, which is why a car can be heard humming or ticking in a garage long after it was switched off. That is normal operation rather than a fault, though a pump that runs on because it never satisfies its test is a genuine cause of a battery going flat overnight.

Also known as: ldp, leak detection pump, evap pump, nvld, natural vacuum leak detection

Referenced by 29 codes

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Codes involving this component (29)

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