Ycb

Hey all, I have the same problem as most of the people here, with the engine stalling at high temperatures and stuff. I have replaced the ignition control module, coils, and fixed the water pump (thought that was the reason for the high temperatures). I got the code reader to run some codes for me, but the place I went to gave me a sheet of paper that shows me a diagramatic layout of my problem. The diagram they gave me was a DTC P0321 Spark Reference Circuit. Here is a copy.







I was wondering if someone could help interpret it for me, and let me know where the PCM is (I think its on the passenger side near the back, a black box with all the wires connected to it???), and if they think the PCM is at fault. Also is it easy to replace? or would a mechanic be needed for something like this.

Any help would be great, because this is my only ride and I need it for school and work.

Thank You

Jim Adams

check under your air cleaner box under hood I know some late model GMs put the puter under the air cleaner,you should be able to take the air cleaner apart and see it there ,,if your cleaner box is on the drivers side front then it may be there.

Jim Adams

The diagrams are pretty much self explanatory,,one tells you how to clear the code and check the voltage in the wire going to the PCM and the other tells you where the wire is located,,I would think that maybe it is a bad connection but if not I would have a mechanic change it because if you dont they will void any warrenty on it because they will think you dont know what you are doing and if it fails prematurely they will figure you hooked it up wrong. They are fairly expensive and I have one out of a buick the same yr and the same engine as this in your diagram,,I got it when I worked at a ford dealership as a frame tech and we got a front clip in to change on this Buick and I wound up with two good pcm,s,,although it probably isnt the same if it is you are more than welcome to it,,it is just sitting here on the shelf ,,didnt want to throw it away at the time I knew it would come to use someday

Ycb

just to update, the problem was the computer.. replaced it.. most problems went away.. ie)stalling, rough idle, and just overall crappiness..

thanks to Jim again!!