Diagnostic Aids

A diagnosed EVAP purge solenoid or EVAP vent solenoid circuit fault may have caused this DTC to set.

PCM uses fuel tank pressure sensor to detect amount of vacuum pulled on EVAP system during leak diagnostic tests. 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.

Use EVAP pressure/purge diagnostic cart and ultrasonic leak detector to locate a small leak.

Possible causes of a small leak:

• Fuel cap leaking.
• EVAP vent solenoid valve not seating correctly.
• EVAP vent hose loose or damaged.
• EVAP canister leaking.
• Fuel sender assembly "O"ring leaking.
• Fuel tank or filler neck leaking.

Small leak diagnostic can only detect a leak more than 0.02" diameter. For potential leak areas, see Figure .