Chrysler Repair: Transmission Problems Codes 0871,1776, napa auto, maintinence

Question
Hello sir,

I have a '02 Concorde Lxi, 130K miles, 3.5 V6.  My check engine light went on while I got off the highway going 75mph.  I suddenly felt my car reving and pushing 3000 rpm steady even though I was only going 35mph.  Basiclly my car felt like it was Like the car was pushing in a gear it didn't need to be at yet.  I took the car to a Firestone, they did a dignostic (I should have read your Q&A's before becuase I would have taken it to a non-franchise place or rented a OBD unit from Napa Auto or Auto Zone for less $).  The codes came up P01776 and P0871. Both have to do with the transmission or hydraulic sensors I think? The 1st place that specializes in transmission I took it too said I should rebuild my trans or replace w/new at a cost of $2400 - $2800.  I'm thinking it could just be a sensor that needs to be replaced because the trans works and my car runs. I picked my car up after 4 days (not quite sure why it took that long but it did?).  And when I drove off the problem was abcent. I haven't gone on the highway again yet though.  Do you think I should take it to a Dealership. I've heard dealers can dick you around as well on what needs to be done vs. what is a costly repair.  Also do you have any thoughts on what the problem could be and the remedy.  I want to go into the next maintinence place prepared and as knowledgable as possible.  Thank you for your help.

Answer
Hi Major,
I would take the car to an independent trans shop that either has a reputation for knowing the Chrysler transmission or claims to do so. The two codes have to do with issues of the switches that control the hydraulic fluid in the solenoid box on the right side of the transmission which can be serviced without removing the transmission of disassembling the main unit. It is typically done by selected repair or total replacement of the solenoid box unit. The first code says there is a problem with the overdrive pressure switch or its sensing circuit, and the second says that the low/reverse pressure switch is either faulty or its sensing circuit is faulty. So I would find such a shop, have them verify the codes, and if they come up with anything other than doing repairs of parts inside the solenoid box, i.e. that is a rebuild, I would go elsewhere. You might want to try doing a transmission power flush and fluid replacement on the hope that the problems would be corrected that way, or at least broach that idea with a shop that you trust. At this point the codes don't point toward a rebuild. I would avoid a dealer unless you know it has a good reputation among owners of the LH cars in your area.
Roland