Yes here is yet another limp mode post.

Car Fine on Friday and Saturday (except for a known EGR problem). Untouched on Sunday. Monday morning its in limp right from startup. Here are the codes:

P0605 - PCM ROM Error
P0403 - EGR Circuit Malf (known)
P0700 - Trans Control Sys Malf

From reading other posts looks like SOP is :

1. Replace filter and Fluid
2. Check and clean input and output speed sensors (Speedo is OK)
3. Check mystery splice under the relay box ??

After that I am not sure. Any help or advice on how to proceed is appreciated.

Thanks in advance. Migs

FIXED: Turns out the codes were all I needed for a diagnosis. Using Alldata I found the shop manual calls for TCM replacement as the only repair. It was replaced and now it works as before. Now to fix the EGR.

I've never seen a PCM ROM error before. Is this my biggest problem ??

Another thing worth mentioning. Some posts mention limp mode as being able shift 1st to 2nd. My van stays in 2nd gear all the time. It does not shift at all. It starts from a dead stop in second gear. I ran it around the block a few times and down the road, up to 50 MPH, for a short run. No change, it only has 2nd gear (and reverse and neutral).

It also seems to jump a bit more than usual when I put into forward or reverse.

I believe your PCM ROM error is fatal. Before spending the bucks I would check with your dealership or a well equipped shop and see if a reprogramming may revive it.

If you haven't yet, disconnect the negative battery cable for a few minutes to clear the codes. There is a tiny chance that may fix something. If the codes come back then you know they weren't just glitches.

El conquistador over on this forum seems to have a handy knowledge of transmission troubleshooting. Send him a PM or post your problem there: http://forum.chryslerminivan.net/showthread.php?t=13537 Disregard the tranny info. Doesn't apply to yours.

Thanks for the info. I did clear the codes with my ODBII gadget but did not try disconnecting the batt. No joy, codes came back right away. I will give the battery a try, nothing to lose but a few min of my time. By the way any idea what a new PCM costs?

$800 from a dealership. $300 online.

Ugh. I tried disconnecting the batt for 15 min. reconnected - No joy. same symptoms. Does anybody have an opinion on the following:

Do I have a PCM and a TCM problem or is one bad component inducing a problem in the other? Thanks.

I see "rebuilt" PCM modules on ebay for $270. Does anyone know what does "rebuilt" mean on these components ? It looks like a sealed box but I am going to take it off for a look see. I have recently fixed one auto component that appeared sealed at first and have seccessfully fixed broken computers. I guess as long as I am careful . . . maybe just a loose chip ???

Took the PCM out and opened it up. Inside is a large circuit board (approx as big as the box itself) completely encased in an amber colored translucent gel . . like a somewhat stiffened but not hardened jello. Wait, not just completely encased, its like they put the circuit board and stuff inside and then filled the enclosure with the "jello". Unless I am willing to remove the "jello" (and I am not), there is nothing I can do. Oh well, I guess a trip to the mechanic or technician or (ugh) the dealer is in order.

I guess the ebay rebuilders can dissolve the jello stuff ?? or maybe they don't do anything besides attempt to reprogram the module.

UPDATE: Even though my ODB II Actron gadget says code P0605 is a PCM ROM error, I know have it from two independent sources that it is a TCM ROM error. This means my problem is in the TCM I can stop even considering problems with the PCM . . for now.