I have searched the forums and Google, but have been unable to find a solution to this problem and hope that someone here can point me in the right direction.

I recently purchased a 2004 Grand Cherokee Limited with the 4.7l, 545RFE transmission and NP247 transfer case. The owner previous to the one I purchased it from had lost the original keys and had the ECU programmed with SKIM delete. He also put on JK 17” rims with 245/75R17 tires by using spacers. Of course, I expected the speedometer to be a little off due to the larger tires, but a little bit off is an understatement. Using GPS, I am doing 65MPH, but the speedometer says I am doing 17-18MPH. The trans kind of hunts for the right gear, and the cruise control won’t even turn on. By ear, the tach seems to be pretty close to accurate. I have checked/tested all the fuses, and all are good.

Question 1: Could the ECU reprogramming have affected the speedometer, gear hunting and cruise control?

Question 2: Would purchasing a used SKIM, key cylinder and matching ECU do any good? I see a few for my year/model/engine on Ebay for about $150, so that is always an option.

I would like to be able to use the remote for locking/unlocking and to have the security feature working.

I can do just about anything mechanical, having been raised in an era of “fix it yourself or walk”, but all the computer stuff is over my head. However, given a direction, I can seem to do what needs to be done.

Thanks

 

Update 11/9/23

After lots of work, I finally replaced the ABS control module, which fixed the issue.