Hi I' new here. I have a 2001 Dodge Dakota v8 4.7 (? not the 5...) automatic 4x4.
This week it died 3 times as I came to a stop, but started right up.
Last night it would not start and had a "no bus" message in the odometer.
I saw a workaround on You Tube to get it to start and get the computer to communicate.
My question is, if I use that workaround and get the truck started, would my code reader diagnose if the PCM was bad?
I'd gladly replace the PCM for about $200 myself, but I'm not confident to trouble shoot it to diagnose if it is the problem.

Thanks for your help!

 

What's the workaround?

 

 

Ok, that's an interesting workaround. Neat way to come up with a five volt signal. His wiring skills leave a bit to be desired though, that's really messy.

I would much prefer to find and fix the problem though. If doing that actually works, it would be a simply matter to just turn the ignition on, and start unplugging sensors on the five volt bus, and see which one you unplug that gives you back the odometer. There's the problem.

 

I agree with HeyYou. Start unplugging sensors.

I wouldn't think PCM right away either. Start doing some troubleshooting.

Common problem areas are the crank position and cam position sensors.

 

That's essentially exactly what the PCM does - Takes Vin, reduces it to 5V for sensors and microprocessor, and there's probably a 3.3V reduction behind that for other logic devices.

 

Yesterday I gave it a try, and it started right up. Drove literally down a long driveway on an errand, left it running 2 minutes, and drove home. Turned it off, restarted, turned off again. If it is still starting today I'll throw the code reader on but there's no check engine light lit up on the dash.
Does this behavior point me in any specific direction?
I called my local mechanic to diagnose, and he said "too much trouble, too complicated, I won't touch it". His only piece of advice was: "remove both battery cables. Touch the cable clamps together for about 10 seconds. Replace. Check for start. If it starts maybe it won't stop again." Didn't have to try it, but I have no piece of mind driving until I'm stuck. Rats, not going to a dealer (I hope).
I'm intimidated by all the sensors but I'll get the manual and come back here for your ever so valued assistance.
I was hoping it was just the PCM and I could throw $200 and be good.
Thanks for you help

 

HEY YOU:
Yes, I think his purpose was to get it communicating so that you could check for a code. It was to help with diagnosis, not as a way to drive. But from what I'm being told here, its not going to show a code that will solve the problem?

 

OK, I will access a manual to locate those sensors and try it. Thanks for giving me a plan

 

Start with the O2 sensors. The rear on OBDII trucks are notorious for this kind of behavior.