So I went to start my 01 Ram 1500 5.2 today and the engine just turned over but wouldnt start. I have never had any problems with starting this truck. Just after that I got a "No Bus" error code. I think that this means that the cluster inst able to talk to the computer?. How would I go about solving this problem. One of my friends suggested resting the ECU. How do I fully reset the ECU and does anyone else have any suggestions?

I read on other posts to check grounds and connections. From what I can see everything looks fine and I don't see how I coulda lost a connection somewhere when my truck was running fine ten minutes before.

One last thing, one of my buddies has a ecu for the same truck truck. Can I plug this right and and see if the problem is solved? Ive heard that the dealer has to program the vin to the ECU, then again these aren't experts I'm talkin to.

Thanks for any insight that can be offered

 

ECU must be same year. motor, trans (auto or manual) and security group (alarm, power locks). If yes it can be swapped.

 

How about if it came from a 5.2 durango with the same options?

 

I'd call B&G Chrysler and ask, they flash PCMs and would probably know if it would work.

 

don't jump to the conclusion that the pcm is bad.

do a search on here for No Bus. its a fairly common problem, and sometimes ends up with it being a bad pcm, but sometimes its a bad ground or a bad sensor. also contact forum member master_tech for some advice, and check out his posts on this.

remove/clean/reattach the ground wires on the PS bracket, engine, firewall. also the group behind drivers side kick panel.

master_tech suggests disconnecting all sensors to see if the problem will clear, then adding them back one at a time to identify which one is bad.

 

I had a "no bus" error and no gauge readings (battery, gas, etc.) whatsoever. Chatted with Dodge online mechanic (for a well spent fee). Using my OBD2 scan tool, we troubleshot to a bad crank position sensor. Apparently, when this sensor goes bad, it takes the bus down with it. So, if you have a "no bus" error and no cluster readings, one of the first thing you can do is disconnect the crank position sensor. It's located on the passenger side, rear of the engine block, directly below the exhaust manifold. Can't miss it, it's the only sensor back there. Once you disconnect it, the car still won't start but if your battery and gas indicators work, then you've fixed your problem. All you have to do now, is replace the crank position sensor and you should be good to go.

 

I had this same problem and bought a new PCM and it didnt fix it. I did some investigating and found the big wad of wires that goes into the main PDC can get wet and corrode and cause this. It looks like a black square with a bolt in the middle of it. I just wiggled it and messed with it and it fixed it. Try that before buying a new PCM