QuestionQUESTION: My car is in limp mode I tried a new out put sensor no luck I cleaned the contacs on the TCM and SBEC when I did that it started working for about 15 mi. then whent back into 2nd gear only.I drove car home.while running in drive Icheck shutdown relay only vots I had was from the alt.to the relay contact there was no volts from TCM to the coil to energize contacts.I put car on ramps and took wire off the PRDNL switch and there was v's going to two of the wires the third that comes from the TCM via splice to shutdown relay had no volts i reconected wires to PRDNL and sudenly the relay coil had volts I drove car and it shifted fine in all gears but OD after a couple of miles it finally shifted into OD then a mile later no gears went into nuetral for 1/2 mile then back into 2nd gear only.I drove car home and while still running checked shutdown relay and again no volts to coil of relay from TCM. Is this sound like a TCM problem?If so is there some where that test the tcm.Can the tCM be intermitent?
ANSWER: Hi Cliff,
I would be inclined to get a readout of the TCM to see if it has any fault codes stored in its memory. There is a blue 6 pin socker on the left end of the dash, near the fuse box, into which a Chrysler DRB II or similar OBD-I reader can be plugged. So either a dealer or an competent independent shop with such a reader can get a 2-digit code, but be aware that they have to program the reader to ask for the tcm code, not the pcm code which is also 2-digit. Then let me know what the number is an we can go from there. I will study the wiring that you described and let you know if I can make any sense of what you experieinced. Be aware that the limp mode is accomplished by opening the trans relay, so that is more likely the tcm having found a fault responding by turning off the relay.
Roland
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QUESTION: that makes sence,I disconected the TCM I was going to take it to a trans part place and get a rebuilt one for 70.00 but if you think it might be ok then if I put it back on will the fault codes still be there.Also do I need to take it to a trans repair place for reading?
ANSWER: Hi Cliff,
No, disconnecting the power to the controller erases the codes, but all you have to do is drive it again, far enough for it to go into limp mode, and that will reset the code(s) that provoked the limp.
You will need to find a shop with the Chrysler DRB II and the data link connector plug or with a Snap-on OBD-I reader and the same plug, or similar professional grade reader, and be sure that their unit has the trans controller program to read it. An independent trans shop would likely be able to do it too. I would avoid a franchise type shop that is mainly focused upon putting in rebuilt replacements, however.
Roland
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QUESTION: Can you buy a reader and the connections to do it your self if so where?
AnswerHi Cliff,
You would have to find a used Chrysler DRB II with the data link connector plug and the program card that covers the '90 model year, which most would have. I bought one on eBay about 5 years ago for around $400. I live in the San Francisco Bay area and I can read it out if you are nearby. But if not, I do believe that there should be an independent repair or transmission shop that has a reader to get the trans fault codes for around $40.
Roland
