I got in the truck last night and when I cranked her up, the headlights and running lights came on automatically. The instrument cluster lights up, but the gauges aren't working. The wiper controlls don't work. My stereo amp is getting power to push the sub, but no sound from the sub. "no bus" displays in the tachometer. I don't know what the problem is. What does this mean? I'm also getting low, erratic rpms while in slow moving traffic. Any help will be appreciated. 03 ram

 

I dont know about the headlights and all. But the rest sounds like the alternator is out. Slow traffic with erratic rpms are what I had when I used to drive my old hyundai. Alternators went out on that thing like every six months, literally!

To test the alternator if you want, start the truck, then disconnect the negative battery cable. If the truck keeps running, your ok. But, if it shuts off, the alternator is dead. Loosen up the cable before you start the truck to make it easier.

 

"no bus" means problems with your pcm.

 

+1 on that. i had to replace the PCM in my durango when it said no bus. if you do a search in the durango forum for no bus youll pull up a ton of good info.

 

a bus in the information between different modules on the truck.

It sounds like one came unplugged, causing the PCM to lose the bus communication

 

Yup, the truck is not communicating with the PCM. Hopefully it's a loose connector, but realistically, your looking at getting a new PCM. Not cheap...

 

I had the same prob on my 02 1500! My dumb *** ex girlfriend turned the ignition on when I was connecting jumpers onto my flat battery!!!!! Result one fried ECU that was bolted to the fusebox! All in all that plus 60k service and new front rotors cost me over $2000 !!!! I think the dumb *** girlfriend part was about $800 fitted!

 

i got my new pcm flashed for my durango with VIN and mileage for like $200. company called soloauto or something. ill try and find the link for you. they were awesome to work with. within hours of placing my order they had called me to confirm the info and had it in the mail for rush shipping that day.

ok heres the link: http://www.solopcms.com/

i found them on ebay. real stand up guys.

 

Thank you! I wish I had known that back then instead of going to the dealers! I know now so if it happens again..................

 

You pull the battery cable with it running and you will need a new PCM. The battery acts as a capacitor to keep voltage spikes from the system. If you alt or regulator has a problem, as soon as you remove the cable, a voltage spike will run thru the system and can fry everything electronic. I have seen vehicles where it blew all of the light bulbs out due to this.
It was fine in the 60's when cars had points. DO NOT do it to a late model vehicle!!