Chrysler Repair: 89 Dynasty 3.0 A604 stuck in low, shade tree mechanic, solenoid pack

Question
Roland,
The tranny was replaced in late '91 after "limping" back to the dealer. Since then it has been basically problem free for another 85k with no maintenance except for several Z-max treatments. We gave the car to our son a year ago and he said it started slipping. He recently replaced the filter with an OEM unit and filled it with "universal" fluid which just made it worse. Since getting the car back I had it to several transmission shops with different diagnosies but one common solution - a complete rebuild. The last place topped off the fluid (3 1/2 qts), cleared out the existing multitude of codes, said the solenoid pack and speed sensors were O.K. but the unit was locked in first gear and had set two codes - I believe they were 36 (faults immediately after shift) and 39 (gear ratio fault). Based on the age of the vehicle and that I'm kind of a shade-tree mechanic myself what do you think is the actual problem and do you think there is anything I can try to fix it?
When I got the car back from our son it only had reverse. The next time I started it up I was able to get first gear but only in L and D, so I drove it to the three closest tranny places. After the trip to that last shop (topped it off and reset the codes) I was able to get first gear also in OD. Is this the learning mode or just some strange behavior from a broken unit? I also did notice that there was a 06/1999 date code on the TCM. Isn't there an improved version of the solenoid pack? Given my situation is there any way to "by-pass" the TCM and connect external switches to the solenoid pack to make it go through the gears? I believe removing 12 volts from the pack will give me just second gear (limp mode).

Thanks for your help,
CB


Answer
Hi Cal,
This is not strange behavior, just limp-in mode, except that I suspect your are driving it in 2nd gear, not low, as that is the default gear for the 'limp-in mode'. About the only possibility beside rebuild due to internal wear out would be if the hydraulic pressures were too low. So it might be worth checking those out. I have the 89' manual that shows what you should measure if you want to try and do that, or have a shop do it. Ratio errors of course can also be due to a worn clutch (one of several such clutches) and so that is the more likely cause of the symptoms you describe. So you might find it to be the pump or something in the solenoid pack, but I would not give it a high likelihood. But the cost of a rebuild is such as to lead one to consider whether it is worth it for vehicle that is 18 years young.
I don't think you can by-pass the controller in any practical way.
Let me know if you want the diagnostic pages and I will xerox and postal mail them to you. Use the "thank and rate" tab where there is a space to tell me an address.
Roland