Canister Purge System

Fig. 17 Canister purge solenoid:

Fig. 18 Canister purge schematic:

The canister purge (CANP) solenoid is a combination solenoid and valve, Fig. 17. The CANP is located in the line between the intake manifold purge fitting and the carbon canister and controls the flow of vapors from the canister to the intake manifold during various engine operating modes, Fig. 18.

The valve is opened and closed by a signal from the ECA. Actual CANP activation modes are part of the calibration. For example, CANP activation occurs when:

1. Engine coolant temperature is greater than ``engine cold'' value and less than ``overheat'' value.
2. Engine speed is above a predetermined value.
3. Time since start up is past a predetermined value.
4. Engine is not operating in the closed throttle mode.

CANP activation continues until the throttle is in a closed position and the engine speed is less than a predetermined value. The CANP solenoid may have a short time delay upon activation or deactivation.