EVAP Pressure Switching Solenoid Inspection

WARNING: This page is about a different car, the 2004 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION: Refer to Fuel Vapors in Evaporative Emission (EVAP) Components Caution in Cautions and Notices.

Fig 1: Measuring Resistance Of EVAP Pressure Switching Solenoid

Courtesy of GENERAL MOTORS CORP.

Remove the EVAP pressure switching solenoid. Refer to Evaporative Emission (EVAP) Pressure Switching Solenoid Replacement (AWD) .
Use a DMM in order to measure the resistance of the EVAP pressure switching solenoid.
Measure: The EVAP pressure switching solenoid resistance is 37-44 ohms at 20°C (68°F).
Replace the EVAP pressure switching solenoid if the resistance is not within the specified range. The solenoid will damage the PCM, if the resistance value is less than 27 ohms.

Fig 2: Checking Continuity Between Terminal To Valve Body

Courtesy of GENERAL MOTORS CORP.

Check for continuity on each terminal to the valve body.
Replace the EVAP pressure switching solenoid if continuity is present. Refer to Evaporative Emission (EVAP) Pressure Switching Solenoid Replacement (AWD) .

Fig 3: Air Blowing Into Inboard Port

Courtesy of GENERAL MOTORS CORP.

Blow air into the inboard port (1). The air should NOT flow through the valve and out of the outboard port (2).
Apply battery voltage across the terminals of the EVAP pressure switching solenoid.
Blow air into the inboard port (1) and air should flow through the valve and out of the outboard port (2).
Replace the EVAP pressure switching solenoid if the solenoid failed either test. Refer to Evaporative Emission (EVAP) Pressure Switching Solenoid Replacement (AWD) .