Circuit/System Verification

Ignition ON and fuel cap removed, verify the FTP sensor parameter is between 1.3-1.7 volts.
- If greater than the specified range, refer to the FTP sensor section in CIRCUIT/SYSTEM TESTING under FUEL SYSTEM DIAGNOSIS in Engine Controls and Fuel - 3.9L - Relay Troubleshooting & Diagnosis article.
With the engine running, the EVAP canister vent solenoid valve open, and the EVAP canister purge solenoid valve commanded to 100 percent, the fuel tank vacuum should not increase to more than 8 inches H2O.
- If greater than the specified range, refer to the restriction section in CIRCUIT/SYSTEM TESTING .