my son has a 2001 montero sport ls. the battery was low so he tried to jump it but crossed the wires. the battery got cooked so we installed a new one. the car started fine bu now it stalls at stops, doesn't upshift, lights on dash that show what gear the car is in are flashing randomly. so what damage was done here?

 

I am guessing he damaged the computer and he is fortunate if that is all that happened. I have seen the results of inexperienced people try to "jump start" their car and end up shorting out the battery and have it explode. Acid burns on the face and premanent reduced vision in the eyes.

Safety at all times when doing anything on a car, and you have to be sure you know what you are doing.

 

Thanks very much for the input. So if the damage is to the computer, is there any guess on what that will mean in terms of repairing or replacing parts?

 

Fortunately, I have not had the privilege of looking to find a ECU (or ECM) for a vehicle. But I know from talking with freinds, there are lots of places online, that sell reman ecu's or can sometimes repair it. The vehicle may have damaged the TCU (transmission control unit) too, that is possible.

Replacing the ECU or TCU is just a matter of removing all the panels and interior parts to get to them and then swapping them out.

It may be money well spent to get the car to someone who can verify that it is the ECU and/or TCU if you plan on doing it yourself. Most places will not take returns on these types of things.

 

Thanks again for this information. Right now it looks like my son will be trying to sell the vehicle as is with a description of the problem. I don't expect that he will get much with about 189,000 miles on it and a leaking valve cover gasket as well as the current problem, but the car's paid off so I guess he'll take what he can get. Starting to wish we hadn't put a brand new battery in it.