I just got this 1998 Dodge Grand Caravan 2 days ago. The people i got it from said the transmission was replaced in Sept. 2006. It has about 20,000 miles on it now. Well i was driving and the transmission did not want to shift out of gear. It does not do it all the time, just sometimes. I took it to my auto parts store and the ran a test on it. The codes that came out was P0715, P0731, and two for P0700. They could not tell me what they ment so i went to the dealership and they told me that they are Trans Codes. I was wondering if anyone can tell me what might be wrong with it? And about how much it might cost to fix. The dealership wanted to charge me $85 just to figure out what it is. I am trying to Save some money and hoping i can get some help from here. Also the service soon light did go back off. Any Help would be greatly appreciated.

Thanks.

 

700 is general transmission fault code
715 is input speed sensor
731 is gear ratio

If your chek engine light isn't on, that is probably good and that they are just stored codes from prior things. If Light is on, you probably need to change the speed sensor. If that does not solve it then you might night a re-flash of the TCM ("Quick-Learn") and that should clear up the shifting. The Speed sensor might be setting off the "gear-ratio" fault and that is why that might fix the whole thing. p0700sets itself usually prior to any other TCM faults, just to let you know something is going on. Good Luck

 

Replace the input sensor and clear your code. When one the two sensor goes dead meaning the tcm controller see zero rpm, then the trans goes into limp in. That is why you have a gear ratio error too.

 

I had this same thing happen on my 98 GC.
I had the Trans. replaced and then in about 20K the light came on. I discovered when I pulled the old sensor it was a mag pickup and there were metal filings attached to it. I went ahead and replaced the sensor but I think if a person were to clean off the sensor it would be fine.

In any case the codes and problems went away as perscribed by the all knowing Master tech.