Need a pcm for a 99 cherokee sport.

If I get one from a junkyard it comes with a 3 year warranty. But can I just take old one out and put the other one out.I keeo seeing it needs programmed for the vin number? Just trying to make sure I do this right.

 

As far as I know programming is not needed but the numbers need to match with exception of the last digit. Do a search here just to be sure about exactly which digits need to match. At the minimum the replacement PCM must come from a an XJ with the same exact options and CA vs. non-CA emissions. What make you think you need to replace the PCM? They tend to last the life of the truck.

 

Gauge clusters go crazy.turn on ac shuts off vehicle.dome lights get super bright when I accelerate.this didnt happen til after I opened the computer to check anything was fried after I put it back in it did this.all this troubleshooting started from an overcharge issue which I put in a new alt and belt.tested this with more then one battery just to make sure it wasnt battery.so makes me think its regulator in computer. I found a computer numbers match except my last 2 letters are AE this one I can get is AF