Fuel Rail Tank Leakage Detection (NAS Only) Tank Leakage Detection Module New Range Rover is equipped with a tank leakage detection system. The system is controlled by the ECM. The tank leakage detection module is located inside the wheel arch at the top of the wheel arch next to the fuel filler neck on a metal bracket.
FUEL DELIVERY SYSTEM – V8 DESCRIPTION AND OPERATION 19-2-9 Leak Detection Normal Operation 1 Throttle plate 2 Air flow to engine 3 Purge valve 4 Charcoal canister 5 Fuel tank 6 Tank leakage detection module 7 Air intake 8 Air filter 9 Change over valve 10 Pump 11 Reference orifice In its inactive state, filtered fresh air enters the evaporative system through the sprung open valve of the tank leakage detection module. When the ECM activates the tank leakage detection module for leak testing, it first activates only the pump motor. This pumps air through a reference orifice (0.5 mm) which causes the electric motor to draw a specific amperage value. This value is then equivalent to the size of the reference orifice. The solenoid valve is then energized which seals the EVAP system and directs the pump output to pressurize the EVAP system. The system is detected as having a large leak if the amperage value is not realized, a small leak if the same reference amperage is realized or no leak if the amperage value is higher than the reference leak value. The leak detection module ensures accurate fuel system leak detection for leaks as small as mm. The pump contains an integral DC motor which is activated directly by the engine control module. The ECM monitors the pump motor operating current as the measurement for detecting leaks. In its inactive state the pump motor and the changeover valve of the DC Motor LDP are not energized. When purge valve operation occurs filtered air enters the fuel system compensating for engine vacuum drawing on the hydrocarbon vapours stored in the charcoal canister. M M19 3566 0.5mm