If you trace the small bore tube from the dump valve back to the bulkhead. Remove the tube, clean the end of it then suck/blow (i can't remember which one), if you can suck/blow the diaphragm has gone in the dump valve and it needs replacing. As Chris already said, check all the vacuum tubing as well for splits/tears and whether they are actually attached.
Ok, what does the "dump valve" look like. So I just check the tube coming off the dump valve. Does this tube go to what is causing the problem. In the picture with the red tubes, is that a picture of what I need to be looking at.
Ok, on the right hand side of the engine bay just behind the radiator will be a black plastic valve with 2 large bore pipes and 1 small thin pipe coming off going to the back of the engine bay (this is the pipe you need)
This is an aftermarket Forge dumpvalve, look for one similar but in black plastic. The Bosch valve is a known weak spot that a lot of Saab owners change out for the Forge replacement.
You can see it better here behind the JR airfilter sticker.
Alright, i found it. Mine is a black plastic Bosch one. On the left side is a metal tube, on the back it goes into a plastic tube, then on the right side is a small rubber tube. I followed the small tube all the way back to the firewall where it connects to a small plastic thing. The tube appears to be in pristine condition. It is not dry or cracking and is still securely attached at both points. You say the dump valve is notorious, is this what is causing my CEL to come on, or is it at the other end, the thing attached to the firewall?
*EDIT* I cannot remove the tube from the firewall to try the suck/blow method. It is securly attached. Would anyone have the part number for the OEM dump valve so I may order a new one.
Uh Oh, I thought this was figured out. Anyway, I was able to remove the small tube from the end of the dump valve. I had a little restistance while blowing in the tube, but almost no resitance while sucking. What is the part number for the other thing, I will try and locate one of those as well.
I have not driven since the light came on, but while I was driving, everything was normal. I noticed the light came on after a nice hard launch from a stop. I looked down noticed the light and continued cruising at 75mph for approx 20 more miles. My wife drove after that and stated that the car drove normal.