Hello all! I'm a new member, posting on my experiences with my 03 Town and Country.

About 3 weeks ago I was driving home from work and my van started running really rough. Once I got home I looked at the plugs thinking bad plug or plug wire and they all looked good but one was different. I swapped back of the engine components to front and tried again but same issue. I took it to Autozone and had the codes read, as stated above, P0203 and P0303. The P0203 keeps popping up after clearing codes and I have not seen the P0303 since the initial read and erase. I bought a cheap code reader and continued trouble shooting.

I read the primary code P0203 as bad injector or bad injector circuit and started by pulling the number 3 injector, firewall side of motor middle injector and swapping it with number 2 injector, radiator side of motor, passenger side. I cleared codes and started the engine. The code was still P0203. I then pulled the harness and checked the common to all plugs (I think it was pin receptacle 2 on all the injector plugs and then checked each number 1 pin receptacle to the pins on the plug. All were good.
A link then said the PCM/ECU mounted in front of the battery was the next think to replace.

I removed the PCM and started looking through the potting compound with a bright flashlight. I found a bank of six transistors and one has a splash of solder and a disturbance in the potting compound around it. Odd though, it doesn't logically sit in a spot number 3 output transistor would be but I don't have a diagram for the box so I've no idea what order they would be in.

My next thoughts are:
1. I don't want to spend $170+ on a new PCM so I'd like to see if anyone has schematics for the PCM for this vehicle that could share...
2. Does anyone know what that specific component is. Describing it as follows: As the PCM sits in the vehicle, the bank of transistors sit above a daughter board behind the upper most plug. They are in the upper half and passenger half of the potted aluminum finned container. The one I think is bad is on the bottom row, driver's side as mounted in the vehicle.

Any thoughts or ideas would be helpful. I did not see any nomenclature other than a bar code under the potting compound so I can't search for anything other than 3.8l 2003 town and country pcm, which didn't yield any results. If I missed a thread I do apologize in advance... If I didn't I'd like to take pictures and document this for the forum.

 

Imgur: Error code P0203 3.8L 2003 Town and Country

Here is the best picture I could get considering how tenacious the potting compound is.

 

I'm thankful for the views but I was hoping to get some help with PCM schematics or something. Has anyone taken one of these apart and tried to fix it?

 

Some resistance before the transistor has to be bad to allow that much voltage. I tried awhile back to get schematics and the books that had them were more expensive than the PCM. The dealer can test the module, but I believe that to is costly. The best deal I found was on a rebuilt, from ebay... If you do find schematics, please post them. Many here find ourselves in your situation.