QuestionQUESTION: please tell me there is a fix for my '91 lebaron 3.0L to go into limp mode. I changed tranny , and relays. it worked for a bit, but went right back to limp upon coming to a stop, with a hard downshift. turn off car, and it will reset for a while. could it be a short to ecm, or tcm? where do i start my troubleshoot, and where do i get wiring diagrams?
ANSWER: Hi Willi,
Earlier this month you asked me a question about a problem with you vehicle. Now I need to ask a favor of you. I am competing for the honor of being the "Expert of the Month" for December. You can help me by going the the 'thank/rate' tab below and look for the question that asks if you think I should be so-honored. If you would select the 'yes' option I would be most appreciative. Please do this before 6pm CST tomorrow, New Year's Eve when the competition ends. I wish that your Chrysler vehicle is running well and gives you good service in the New Year!
Roland
Hi Willi,
Did you really change the entire 'tranny'? Or just the controller?
In any case, the best way to trouble shoot this is to do a fault code readout of the trans controller memory. There is a blue socket under the dash near the fuse box which couples to the trans controller via the digital data bus wires. It has a 6-pin (2 x 3) pin arrangement that is different from the connector in the engine compartment that accesses the engine controller. A shop with a Chrysler DRB II reader or anyother professional analyzer that has the specific plug can get the fault codes, which are 2-digit numbers. But make sure the readout is of the trans controller, not the engine controller, which also has 2-digit fault codes. Write back when you get the number(s) and we can see what the manual says might be the solution. I have the wiring diagrams and can xerox and postal mail them to you, but this is probably not a wiring issue.
Roland
PS Use the 'thank/rate' tab to get back to me without having to wait for me to be 'available' to take a message. There is a space for comments, to which I will respond.
---------- FOLLOW-UP ----------
QUESTION: ok roland the car is driving, but i have to shift into nuetral to come to stop. otherwise there is a hard 2-1 downshift causing stall and limp mode. is there a way to reset engine and tranny without a code reader (i recentely lost my job and am out of funds), or a bypass for solenoids, tests i can do w/ multimeter. please you're my only hope. i need to drive this car 600 miles for some work, but don't know if it's wise without reset
AnswerHi Willi,
Unfortnuately I know of no way to readout the transmission controller's memory or to manipulate the transmission function without a digital interface thruough the blue plug using either the Chrysler DRB II or a Snap-on Scanner or equivalent. There are so many possible reasons for the harsh downshift and and lock-up/stall that you have to get a readout to know what to troubleshoot. There may be a shop in your area with a scanner that can communicate via the blue plug, give you the codes and we can go from there. Ideally they won't charge you too much for just that.
I can xerox copy and mail you the wiring diagram for the connecting plugs between the transmission and the engine controller so that you can verify that the wiring is or is not the problem but that is about all that can be done without a digital reader. Let me know a postal mailing address to which to send the diagrams.
Roland
