Dodge Repair Questions? Ask a Mechanic for Answers ASAP
Incorrect ratio codes (p1790) almost always indicate a mechanical failure in the transmission, but they are almost always accompanied by slipping. I think you are on the right track with disconnecting the battery to try and reset the TCM. It could be setting a false ratio code. At this point it might be best to have it towed to a transmission shop since you might not be able to get the TCM to reset without pulling the battery cable.
Did you try to remove the transmission control relay yet?
Here is a picture of it's location.
If this relay were bad you wouldn't get 1st or 2nd gear, only 3rd. Since you have 1st and 2nd and no third, I hate to say it, but you probably have an internal mechanical failure and will need a transmission rebuild.
Please let me know if you need additional information.
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