Tranny dilemma

I have a dilemma. My 2004 Chrysler Concord with 92K miles went into limp-home mode on a couple of occasions over the past year. Two tranny shops (not chains) and a dealer took code readings but only came up with P0700 ?Transmission Control System?. The tranny works well in all other respects.



The last tranny shop (in business for the past 30 years) finally recommended, based on recent similar experience, replacing the ECU which also included the TCU. Now my dilemma; an OEM TCU is available for about $550 plus installation labor, but then it needs to be flashed. So I?m looking at about$850-$900. I located an outfit in Miami that offers refurbished units for $245 that are warranted for life (whatever that means), plus are plug-and-play ready. No need to flash the system. They only require that the battery be disconnected for about a half hour to allow the system to become normalized. In both instances, the OEM and the refurbisher only needed the VIN and mileage reading. Does this sound plausible? Has anyone else run into this?

Thanks.



Have you priced a salvage yard ECU/TCU? I don’t believe that anybody actually “refurbishes” ECU’s, they’re just picking them out of wrecked cars and giving you a mark-up.

I understand that. I’ve been informed that even getting one from the junk yard will need to be flashed when installed. What I am looking to find out is whether a replacement unit can truely be programmed at the supplier so that it truely is plug-and-play as advertised.

Is it limp mode all the time or just intermittantly?? What I am getting at here and I have seen this many times before is that the code doesnt store. You got a P0700 which is a generic code indicating a problem with the transmission. With that P0700 should be another code, a manufacturer specific code coming from the TCM. I would have the computer scanned while it is in limp mode. Dont shut the ignition off because sometimes cycling the ignition will clear a code. Maybe when these shops were scanning, the computer wasnt in limp mode. Just a thought because I have seen this before. Make sure you do need an ECU/TCU BEFORE you go spending the money on it. They just dont go bad that often and I would hate to see you spend that money when you dont need to.

transman

When it goes into limp mode, I have simply turned off the engine for a minute or so. When restarted, the tranny shifted OK except that the CEL remained on. And yes, each time the shop looked at it, the limp mode had passed.

Thanks for your input.