Canister Purge Solenoid: Testing and Inspection

Chart 6EC-1:

Wiring Diagram:

CIRCUIT DESCRIPTION
The EVAP solenoid receives 12 volts from fuse "D1" in the engine compartment fuse block through CKT 750. The PCM energizes the EVAP solenoid by grounding pin "3E7". When the solenoid is energized it allows the EVAP canister to purge.

The canister is commanded by the PCM to purge when:

1. Coolant is above 80°C.
2. Closed loop has been achieved for at least 30 seconds.
3. The throttle switch is open.
4. Vehicle speed greater than 10 m.p.h..
5. Engine speed (RPM) above a threshold.
OR
6. Code P013, P017, P042, P043, P044, or P045 is present.

The PCM will de-energize the solenoid when codes P016 or the PCM is running in the backup mode.

If the solenoid is closed, (not receiving power or has a stuck plunger), the canister will not purge to the intake manifold. This will prevent the canister from purging fuel vapors and could result in a complaint of fuel odors coming from the engine compartment.


PROCEDURE
1. Attach hose to vapor line that comes from canister to solenoid and attempt to blow into it. Air should not pass into solenoid. If air passes through solenoid, then replace solenoid.

2. With engine "OFF", go into EVAP solenoid override (PO01). Override of solenoid should cause solenoid to vibrate. Physically touch solenoid (mounted in engine compartment) in override condition. If solenoid is not vibrating, then replace solenoid.

3. With the solenoid vibrating, attach hose to vapor line that comes from canister to solenoid and attempt to blow into it. There should be a noticeable difference in resistance from step 1.