Intermitten SES indicator

[kuhnzoo]

I have read the information Sattech (and others) posted relative to Code 26. Very good info. I have the infamous intermitten SES (at idle and for a few moments after initial acceleration) on my 1992 SL2 which has 165,000 miles. All of the simple items (indicator lights, speedo, cooling fan) check out OK, I just have a couple of questions about the others...

I checked the EGR solenoid valve for coil resistance and it was in spec (37 - 44 ohms). While this tells me the solenoid coil is OK (no short or open ckt), it does not tell me if the solenoid is functioning properly. Is the solenoid valve normally "open" or "closed"; by normally, I mean without any electrical or vacuum signal to the valve. What is the voltage signal (5V, 12V?) sent to the solenoid valve coil so I can check actual solenoid valve movement.

Secondly, where is the cannister purge solenoid valve located? I see the vacuum tube drop off behind the engine underneath the intake manifold, but it was a bit snowy and icy on the ground to want to crawl under the car to locate the valve. Or is that my only choice? If this solenoid were to malfunction, could it cause a fuel leak from the purge system?

Lastly, some sort of A/C ckt function was associated with the Code 26. What is the fault in the A/C ckt that would set a Code 26? And would it be intermitten? I checked my A/C and noticed (to my dismay) that the compressor clutch did not engage when I turned on the unit! I haven't traced down that problem as of yet.

Thanks for any assistance!

[ssicarman]

Most commom code 26 problem is either the EGR solenoid or the cannister purge solenoid. The solenoids usually go bad with a hot engine, so if you did your measurements on a cold engine they would likely show as good. The cannister purge solenoid is on the back of the engine above/behind the starter. The cannister purge solenoid deals with vapours only. Don't know for sure but the EGR solenoid should be normally closed as it doesn't allow vacumn through it until it's activated. As to your A/C, you say that you didn't want to crawl under the car due to the snow and ice, the A/C will not operate below certain temperatures: as in the snow and ice. It would serve no purpose to run it then, so there is a good chance that there is nothing wrong with it.