Chrysler Repair: 90 Mini-Van :transmission codes 0500, 0731, dodge grand caravan, postal mail

Question
Hi Roland,

My grandsons 1999 Dodge grand caravan 3.3 a/t had a speedometer failure, a stalling, and 3 codes thrown...500, 700 and 731.

He finally got it restarted and drove home and noticed a "burning smell" when he got it in the garage.

It's still sitting there while we try and get some info on what happened...with a few phone calls to dealerships he has been given ballpark figures of up to $4,000 to fix it.

Any thoughts on this one?

Thanks in advance..

ERic

Answer
Hi Eric,
What you were told (spending $4000 to replace the transmission) is likely a rip-off, because there is another possibilty that should be pursued. The 0731 code, by itself says that the ratio between the speed of the input sensor and the output sensor of the transmission is incorrect and suggests that the first gear clutch is slipping which requires rebuilding the transmission. BUT, the 0500 code says that the 'output speed sensor' signal is missing in action which could be the cause of the 0731 code. So the best thing to do is try replacing the output speed sensor (which can be done yourself; it is located on the side of the transmission facing the front of the car, at the very far end of that side). It unscrews/screws in like a spark plug and is tightened to about the same torque. Remove its electrical plug by gently lifting the tab on the side, and pulling it off.* You might have to get at it from underneath or by removing items above and going in from the top. It costs less than $100. That should restore the speedo function unless the problem is one of the sensor wires instead is shorted to ground. I can copy and postal mail you the wiring diagram so you can check that out using a volt-ohmmeter.
If doing both those things don't fix it, then you can have a competent independent shop go through the tests to solve the 0731 code which may conclude a rebuild is necessary, but not for sure because there are other possible reasons that the testing will reveal.
By the way are you sure this is a 1990 model? It shouldn't have 4-digit fault code numbers unless it were a '96 or later model year.
Roland
PS: The 0700 just reports that there is a transmission fault code that is specific also stored in the memory. Note that the input speed sensor looks just like the output, but it is located near the front of the transmission, on the same side as the output sensor.