Fuel Tank Pressure Sensor Reading - keywords evap P0442 P0446 P0451 P0452 P0453 P0455 P0496

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

When diagnosing a EVAP system DTC on a 2005 Corvette, the technician may notice two fuel tank pressure sensor parameters.

This is a scan tool software concern, and there should not be two fuel tank pressure sensor readings. The scan tool pressure sensor values may be incorrect with the key on engine off, and the fuel cap removed. When the fuel cap is removed the Fuel Tank Pressure Sensor reading should be -1 to +1 inches H2O.

If the fuel tank pressure sensor reading is not reading -1 to +1 inches H2O, use the Fuel Tank Pressure Sensor voltage readings to verify proper sensor operation.

Voltage reading between 1.3 to 1.7 is near 0 inches H2O.

Voltage reading lower than 1.3 to 1.7 indicates positive pressure.

Voltage reading greater than 1.3 to 1.7 indicates negative pressure.

If the Fuel Tank Pressure Sensor voltage is between 1.3 to 1.7 volts with the fuel cap removed, this reading is near 0 inches H2O.

Continue with written SI diagnostics as needed.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.