This is what I found for you. Let me know if it helps.
For 1987 and later models only, except L-body
Description: Purge canister/EGR solenoid circuit is open or shorted
Bad connection or wiring - Check the wiring and connections between the logic module and the solenoid. Clean and regrease any corroded connectors with dielectric grease and repair any shorts.
Bad solenoid - The solenoid is located in the right, front fender next to one to three other solenoids. See the Understanding Solenoids page for information about how to test and repair solenoids.
- Near 0V or near 12V not detected when the solenoid is turned on or off, respectively
Results If Component Fails
Fault code 31 is stored.
Monday, June 21st, 2010 AT 11:16 PM