2001 3.3L PCM problem?

The dealer says we have a bad PCM. Van runs fine. SES light is on and odometer/tach doen't work. They want $600 for a rebuilt one. Junk yard sales em for $200 but on the 2001 and newer they can no longer be swapped. Why is this? Is there a way around it?

What's the SES light? Slow down because I once ended up paying 580.00 for a hole in a hose! the dealer replaced PCM and the code came back again. Replaced a pump after that(evacuation pump?...can't remember the name at the moment and too lazy to look it up) That still didn't fix the problem because believe it or not it also had a broken wire and a hose with a hole in it! Pissed me off! Inept mechanic was 1/2 the problem, Inept owner was the other half(that was me). I can help you with 1/2 the ineptness....maybe. Hose had hole in it...mech reads computer code for problem. Replaces PCM but doesn't fix problem. Replaces pump because that is next on list. Doesn't correct. Now that the computer is out of ideas he starts to do a "Good visual inspection", finds either the broken wire to the PCM or the hole in the hose. Don't know which order.
Probably hole in hose rubbed through, but during process of swapping expensive parts, pulled a wire off PCM. All is said and done 580.00 bucks for a broken hose. Couldn't get pump or PCM back...They were long gone. So I was told.

Long story longer...."Never Underestimate the value of a good visual inspection". I learned that from a extremely smart troubleshooter.

What's the SES light?

The dealer says we have a bad PCM. Van runs fine. SES light is on and odometer/tach doen't work. They want $600 for a rebuilt one. Junk yard sales em for $200 but on the 2001 and newer they can no longer be swapped. Why is this? Is there a way around it?
How many miles on the van , I thought the PCM's were under warranty for 80000 miles as a emission item . also I would pull the IOD fuse in the power dist center under the hood , this will sometimes fix dash anomalies by killing power to the BCM .

SES=Service Engine Soon, Mileage = 105K, IOD fuse, I looked for that, where is it? in the fuse box with the others? Funny thing, speedometer started working on its on today

SES=Service Engine Soon, Mileage = 105K, IOD fuse, I looked for that, where is it? in the fuse box with the others? Funny thing, speedometer started working on its on today
IOD is in the fuse and relay center under the hood above the battery , usually near the top of the box .

JL, do yourself a favor and disconnect the battery and clean the + and - posts real good. Also clean the cables. Make sure the battery is disconnected for 10 minutes while doing this. Also make sure the cable that goes from battery - to chassis has a good, clean ground. Re-connect and see if this doesn't take care of your problems.
I believe you have a poor ground issue. I had one just like this. Speedometer wouldn't work and then one day it was working again type thing. When your cleaning the battery cables, you are also resetting the comunication modules(PCM,BCM..etc etc ).
Let us know how you make out.