Diagnostic code

2000 Jeep Cherokee Sport. On a simple diagnostic check by turning ingnition to ON-OFF,ON-OFF, ON the display in the odometor window reads NO BUS. What does this mean?

Your vehicles various control modules are not communicating with each other correctly. This is a problem best handled by a jeep dealer as they have the tools necessary to comprehensively manipulate your vehicles electronics.

Was the check engine light on?? The best way to do a diagnostic check on any computer controlled vehicle is with a scanner. I never believed in those key dance, paperclip in the ALDL and read the flashing lights methods. Too many people misunderstand the lights, put the paperclip in the wrong connector or try to paperclip an OBD II connector. The scanner is the best way. It will tell you the code and the meaning of the code and you can even read live data, and without the risk of damaging the computer.

transman

The scanner is the best way. It will tell you the code and the meaning of the code and you can even read live data, and without the risk of damaging the computer.

Actually, the key dance is (if the car has it) usually pretty good as it is just an alternate way of reading out a simplified version of the engine codes. And if you do it wrong, you just don’t get any readout.

But in this case, I think you are right. A scanner would be the next step. Unfortunately, in this case the odds are that it is going to say that it can’t connect to the computer. But that’d be a good thing to confirm before going further.

Had to replace the the Crankshaft position sensor to correct bigger problem. The NO BUS indication disapppered. Thanks for your thoughts anyway.

Some folks who post here are really dealer shills. Not really helping just soft selling dealer repairs. On the other hand you gave no average good mechanic anything to help you with. No symptoms, actually you gave no problem at all. Look if you are really looking for help give us info or just go to the dealer. This is pointless.

Some folks who post here are really dealer shills. Not really helping just soft selling dealer repairs.

Who? Transman? Vtcodger? Xebadaih? These guys have been here for years helping people with their problems. Dealer shills? You can only wish you were as helpful as these guys.

Did not intend to waste your time. Still have no real answer to the NO BUS indication. Just thought someone had an easy answer. (I’m certainly no dealer shill) No response expected.

The “NO BUS” warning indicates the communications bus that the electronic systems use to communicate between each other isn’t working. This could be due to several things but the most likely things are either the power for the bus has been cut off somewhere or possibly there is a broken connection. Check the fuses under the hood and inside the cab for any bad ones.

Thanks, Cougar. I’ll check.

But if you hook up a scanner and manually command as session with other parts of the system you will be able to see if the code its self was in error.

This is just what I was trying to say. After your key dance, you got a No bus error which all of a sudden disappeared. Its entirely possible that this is just a fluke code which popped up from the key dance. Think about it, what are you doing when you key dance looking for codes? You are applying power to different parts of the computer then removing power then applying then removing then applying then removing then applying the power at a quick rate. Try doing that with your television, flip it on and off 5 or 6 times real fast, it could also throw up an error code. What happens when your PC starts acting up, you power it down and reboot which most of the time solves your issue. Vehicle computers are no different and can pop up fluke error codes. Unless the code keeps coming back, thats probably why this code came up. An actual no bus problem would probably have kept the vehicle from running at all. Me soft selling dealer repairs?? I just told the OP the best way to check this is with a scanner. Almost any independant shop around has some sort of scan tool. I dont work for a dealer but I have $10,000 worth of scan tool sitting in my shop.

transman