Do the EGR solenoids work? My simple test.

After reading of several ways to check whether the solenoids activate, it dawned on me
that a simple 9 volt battery should do the job. If the solenoid is good, it should "click" when activated momentarily and using a 9 volt alkaline battery on a 12 volt coil shouldn't do any harm.

Using two clip leads, I connected a 9 volt + (positive) to the EGR input pin "D" then using a paper clip attached to the - (negative) on the other clip lead, I momentarily touched the remaining three pins, A, B, C, which are the negative sides of each solenoid. At each touch I got a healthy "click" from the solenoid activation. 

That simple solenoid activation (click) doesn't tell me anything about how the PCM/EGR
combination is performing under driving conditions but it is a quick and easy way to assure me that my solenoids activate when voltage is applied.

EGR Base Gasket Leak

Another source of confusion is the Base Gasket.
You may find EGR Base Gaskets advertised for about $5.00 to $6.00.

But don't confuse an advertised Base Gasket with the
Insulator Gasket. On the exploded view of an EGR assembly, Item #3 is the EGR Base Gasket and Item #4 is the Insulator Gasket. 

Some advertisements are selling Insulator Gaskets but calling them Base Gaskets. According to Tomco, Inc,
the actual (#3) Base Gasket is not an item that can be bought.

"We have seen a number of Digital EGR valves that have blown the gasket out between the EGR base plate and the EGR base. Since this gasket is not sold separately the whole valve must be replaced. A good service practice is to tighten the screws that hold the EGR base plate and base together. This may prevent premature failure of the gasket."   TOMCO TECHTIPS Issue 29

1994 Oldsmobile Cutlass Ciera S 3.1 V-6 Engine Code "M"
My Digital EGR

My EGR remarks don't cover subjects such as carbon buildup, PCM (computer) problems, other sensors, or mechanical problems that might interfere with the EGR.

There are literally thousands of posts on the Internet that explain all these subjects
very well. I'm simply posting some of the EGR information and situations that I've encountered so far.

Here is the original EGR as it was while on my engine. See the "crud"
leaking around the base plate? That is evidence of a leaking Base Gasket.
Below is a picture of the same EGR after it was removed from the engine. The "crud" is all around the EGR base.
The screws were all tight so the gasket
 itself had failed.

The leaking Base Gasket cannot be purchased according to Tomco Tips (see quote above).

Above is a picture of the old  EGR bottom with the Insulator Gasket still attached. The Insulator Gasket is available at most auto parts stores but don't confuse that gasket with the Base Gasket. All that black stuff is carbon buildup that has blocked the passageways through the EGR. This is the condition of my old EGR after 118,000 miles of use.