Chrysler’s NVLD, or Natural Vacuum Leak Detection, system was first introduced in 2002 as an
alternative to its Leak Detection Pump (LDP) method for the onboard testing of the evaporative emissions system. In
an automotive application, the fuel system is sealed when the vehicle is in a key off condition. The powertrain
control module (PCM) monitors the state of a switch contained within the NVLD assembly.