4.0cherokee

Okay to start things off. I have 3 xj's 2 99 and 1 96. I have a friend who wanted one and we found an 01 sport with 105k. We went to buy it and the gauges worked. The temp,oil preassure , speed and tach. Everything functioned as it should. Turned the jeep off paid the older lady who had it the 2k and we went home. From the moment that we gave her the money the gauges haven't work. We get a no bus.

Things we have tried.

Hitting the dash

Cluster passes function test when using the push the button and turn the key

No codes other than no bus signal

Pulled dash and cleaned plugs

Tried twisting the prongs

Went to Mopar and bought a new plug that goes to the back of the cluster and soldered that in. (Twisted the bus wires together as FMS says)

We are getting 2.4V at the OBII port like we are supposed to as well as at cluster.

Unplugged every sensor one at a time in an attempt to illuminate a short.

Tried to twist some 14g wires and go straight from pin 28 and 30 on the ecm to the dash and bypass everything in the bus system.

Removed and cleaned all the grounds in the engine bay.

Dropped jeep off at automotive shop and they spend several hours with no luck.

Previous owner had also tried to fix issue with their mechanics.

The jeep starts, runs, and drives just fine. The only thing we have left is wiring somewhere and also replacing the computer. I only have computers from my 99's and 96. I am tempted to plug those in to his jeep just to see if we get a no bus issue then. I am sure I would not be able to start the jeep since it has coils, but maybe help with the no bus issue.

At this point he doesn't want to spend more money and get a wiring harness from ebay. He is to the point where he would rather spend the 500 for an aftermarket dash and wiring in the necessary gauges. I also has the 01 FSM and have unplugged all the sensors in the bus system. Nothing has changed our no gauge situation. What is left to try other than the ECM because he just wants to drive his jeep. He bought it and its been down 3 weeks because of this issue.
Thanks,
Dave

fb97xj1

See if swapping clusters from one of the 99s get you anywhere.

TrailerTrash

My stepdad had the exact same problem in his 02 Ram 1500. It wasnt constant but youd start the truck and No Bus+no gauges. then ti would flicker then go away then come back ect.

After all kinds of things that didnt work, I grabbed the computer connectors and wiggled the hell out of them all. the truck stumbled but stayed running and its been a year and a half now the problem never came back. I guess one was loose enoughh to cause an issue but not bad enough to keep the truck from running

4.0cherokee

I can try the dash swap I guess, but it does pass the check. We have plugged and unplugged the ecm several times checking for bad connections there as well.

Turbo X_J

Check/clean the harness for the CPS?

jordan96xj

If the dash assembly is not properly grounded to the chassis of the vehicle, it can cause bus issues as well. Has the assembly been out for heater core or anything?

This video shows what I am talking about - they finally figure it out at the 30:30 mark.

4.0cherokee

Alright and the winner goes to fb97xj1. We finally just got frustrated enough and pulled the cluster from my 99 and Wallah they worked perfect. So he bought one off of ebay. He will eventually get it reprogrammed for the correct mileage, but for now he can at least drive it. I hope this can help somebody else out in the future that has some no bus issues and has checked all of the normal things.

fb97xj1

Awesome. Hope the fix sticks. Sounds like the microprocessor in the cluster failed, or atleast part of it.