Leak Detection Pump (Spectra)

To test EVAP system for leaks, ECM command Leak Detection Pump (LDP) valve to open and close. LDP valve is heated and can completely eliminate the humidity factor when in test mode. LDP can be identified by a 4-pin connector terminal. LDP is located at rear of vehicle near EVAP canister and fuel tank. See FUEL EVAPORATION SYSTEM  under EMISSION SYSTEMS.