Well I don't know if you have the van running yet. I was a tech for a GM dealer for 13 yrs. After that I've worked at a Toyota, Scion, VW & Audi dealer for the last 2 years. I'm an ASE certified master technician, with L1 & X1 qualifications. If you haven't figured it out yet, I will send you a PM with my home phone # & I'll do my best to help you out. There are several things that need to be checked to find out the cause & with my lack of typing skills, would take too long to list. You don't need a scantool to get the codes, you can flash the codes out on the check engine lamp by shorting the correct pins on the dlc connector.