Circuit/System Testing

Restriction

1. With the engine running, the EVAP vent solenoid valve open, and the EVAP purge solenoid valve commanded to 100 %, the fuel tank vacuum should not increase to greater than -15 mm Hg (-8 in H2O).
   • If greater than the specified range 
   1. Isolate the restriction by disconnecting one component at a time
      • Locate and repair restriction
   • If within the specified range 
2. Using the scan tool decrease the canister purge duty cycle from 100 % to 0 %. The vacuum should decrease to near zero.
   • If the vacuum did not decrease to near zero. 
   1. Inspect the components in the EVAP vent system for a restriction
      • Locate and repair restriction
      • If the vacuum decreased to near zero. 
3. All OK

Fuel Tank Pressure Sensor

1. Ignition OFF, all vehicle systems OFF, this may take up to 2 min for all vehicle systems to power down.
2. Test for less than 5 Ω between the low reference circuit terminal and ground.
   • If 5 Ω or greater 
   1. Ignition OFF, disconnect the harness connector at the B150 Fuel Tank Pressure Sensor.
   2. Test for less than 5 Ω in the low reference circuit end to end.
      • If 5 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 5 Ω, replace the B150 Fuel Tank Pressure Sensor
   • If less than 5 Ω 
3. Replace the B150 Fuel Tank Pressure Sensor