Test Description

The numbers below refer to the step numbers in the diagnostic procedures.

1. 3  - This step verifies that DTC P0442 is captured in freeze frame/failure record list. When multiple EVAP system DTCs are set, DTC stored in freeze frame/failure record is the preferred diagnostic starting point.
2. 5  - Fuel filler pipe has two vent lines that allow for recirculation of fuel vapors between fuel filler pipe and fuel tank. Because of these vent lines, EEST can be connected to the EVAP service port for leak detection. Waiting until smoke is seen before plugging EVAP canister drain hose speeds up the filling of the canister with smoke. Introducing smoke in between 60 second intervals of Nitrogen will speed up the filling of smoke in the fuel tank and filler pipe vapor space. This occurs because pressure at which Nitrogen gas is applied is greater than pressure at which smoke is introduced. Nitrogen gas pushes the smoke that was just introduced through the canister and into the fuel tank.
3. 7  - This test verifies that the Fuel Tank Pressure (FTP) sensor is accurate. An FTP sensor that does not correctly respond to vacuum, or pressure may cause this DTC to set.