O.K., I'm too cheap, for now, to pay someone to figure out what the source of the code 54 and 55 is on my 93 SSE. I got some good information on my last post and I have been trying to investigate how to test the EGR and associated wiring. While trying to check the EGR with a digital volt ohm, I ran across some confusing information regarding pin location on the EGR itself.

Stay with me on this....the connection point on the EGR is in the shape of a pyramid with rounded off points.

According to Chiltons (diagram), the top point connector pin is D, the middle is B, the left bottom is C and the right bottom is A. (I had to draw a picture to keep it straight).

According to Chiltons (picture), the top point connector pin is A, the middle is B, the left bottom is C and the right bottom is D.

Confused, I consulted the Internet and found Wells Corp and the test procedures for the GM digital EGR.

According to Wells, the top point connector pin is A, the middle is B, the left bottom is C and the right bottom is D. That matches the Chiltons picture.

I am assuming that since the ohms specifications use the D (or is it A) contact as the common reference, it will make a big difference in the readings and a determination on the condition of the valve?

The next difference is the ohms reference......
Chiltons
A - D 20 TO 30 Ohms
B - D 20 TO 30 Ohms
C - D 10 TO 17 Ohms

Wells
A - B 20 Ohms
A - C 10 TO 17 Ohms
A - D 20 TO 30 Ohms

Can someone help me out on which one to use? If fuddy knows more about this kind of stuff, how can I make sure he see'* this? Is that being too pushy?

O.K. now I really feel stupid. I went back out and turned on the flash light and I can now see the plug is labeled. I have the correct pins and the readings. Which readings are right? Wells or Chiltons?

I had a bad somethingo r other related to my EGR valve. (on my '87 bonnie) I kept on getting ode 32. So what I did was just buy a new valve and solenoid. After its all said and done I think I might have just needed a new egr solenoid but since I had boughten the valve first (gm parts direct has good prices on them if you're in the states... just letting you know, I DONT work for them etc). But then again with the newer egr valves like the one on yours there may be more to it. Mine'* a regular old vacuum operated 'negative back pressure' or whatever valve, is yours a digital one? Or is it linear?
Tell me how it goes,
Mike D

Mine is the digital egr. It actually is a new valve from a local parts store. The old valve was only 15 months old and was a gm part installed at a local dealer. The same dealer was the one who tested and told me it was defective. The new valve has been in place for a couple of weeks, but I still get a daily SES light. On for 20 or 30 miles, off for 20 or 30 miles. I was testing to verify that the valve was good as I know that not all new parts are good. It is a Borg/Warner valve and has a lifetime replacement on it. GM parts direct had it for 194 US and I was able to go through a friend of a friend and got it for 150.

In my reading I found an article that said a clogged catalytic converter could show up as the EGR having problems. Not sure about this, but plan on getting a back pressure test next week to verify no problems. Makes sense to me especially since the light is on and off.

Looking at the wiring harness (not the EGR) - The top of the pyramid is "A," below it is "B," and then the left side bottom is "D," and the right side bottom is "C." This is from the back of the service manual.

A - Light Blue
B - Brown
C - Red
D - Black

Oh no! the EGR page in the factory service manual is different.

"D" is on top, "B" is underneath that, "A" is bottom left, and "C" is bottom right. That'* wonderful - I've seen the dealer manual do this before. Probably the best way is to go by the color.

Black - Ground
Light Blue - Solenoid No. 1
Brown - Solenoid No. 2
Red - Solenoid No. 3

Code 53 means the No. 1 is malfunctioning. Code 54 means the No. 2 is malfunctioning, Code 55 means the No. 3 is malfunctioning.

Thanks fuddy

I've got the letters and colors matched. I don't have a light blue wire so I guess that goes along with what I read on another post that the bonnies don't use the #1 solenoid. On the car the ohms read
A - D 24ohms
B - D 24.5 ohms
C - D 13.0 ohms.

both solenoids that are used activate and affect the running as describe in the manual. The wiring was checked and repaired by the local shop the first time this came up.
Any thoughts on the statement about the cat and back pressure affecting the EGR?

I'm just exploring.

I hook up the unused solenoid to help pass smog test ,does anybody know why it'* not used on 92-93 bonne?

I thought that the */C engine used 2 solenoids, and the regular engine used all 3. Did you check the EGR out for restrictions or a carbon buildup?

Someone else will have to speak to the plugged CAT, I'm not sure.