Diagnostic Aids

ECM uses fuel tank pressure sensor to detect vacuum decay of EVAP vent solenoid diagnostic. Ensure fuel pressure sensor is not skewed by verifying FUEL TANK PRESS. SENSOR on scan tool is 2.35-2.85 volts with ignition on and fuel cap removed.

DTC is most likely caused by a faulty EVAP canister purge solenoid valve. An intermittent DTC may be caused by a faulty EVAP canister that has released carbon particles and resulted in EVAP canister purge solenoid valve leakage. DTC is most likely caused by a faulty EVAP pressure switching solenoid. Check EVAP pressure switching solenoid for faulty connections and erratic operation. Check for problems in any of the following components or for any of the following conditions:

• Missing or leaking "O" rings at fuel vapor lines.
• Cracked or damaged EVAP canister.
• Damaged source vacuum line, EVAP purge line, EVAP vent hose or fuel tank vapor line.
• EVAP vent solenoid is stuck open.
• EVAP service port valve leak.

Perform an inspection of all EVAP system components and vacuum hoses. See underhood vehicle emission control information label for component identification and vacuum hose routing.