Hey there, first post in a very long while.

I am a Jeep enthusiast and gear head trying to help my parents out and fix their 2004 VDP.

I recently replaced their fuel pump because it was completely bad. We got a used pump from Coventry West right here in Atlanta. All went well, was MUCH easier than I thought it would be with the little trap doors under the back seat, genius move on the engineers! Now I have a myriad of new issues. I am getting one code, P1637. I have fault messages on the dash for DSC, ABS, Park Brake, Low Brake Fluid (fluid is not actually low), I am also not getting vehicle speed on the speedometer, and I am sure there are a few I am forgetting but the P1637 seems to indicate a CAN malfunction between the ECM, TSC, and ABS modules. I seem to find a lot of info reference the 98-03 XJs and the XKs but not much about these issues and the 2003 and newer XJs.

Can anyone help advise me on where to start?

 

I had the same exact problem with my xj8, I found it to be a broken ground bolt behind right side headlight, there is two ground bolts there mine was the lower one that was broken, be careful tightening them as they are aluminum as well. Good luck!

 

As Robertnashleyj states, all these errors together is usually a sign of a ground problem at the front of the car. I replaced mine which fixed all the issues. One of mine snapped completely off when I undone the nut.