(Not a A-Body) 2001 Dodge Ram Truck "No bus" Code, Anyone!?

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alleyoopmgv

alleyoopmgv

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(Not a A-Body) 2001 Dodge Ram Truck "No bus" Code, Anyone!?

The truck turns over, but it wont start. Has anyone have any idea's??
 
Dreaded "no bus"...Was PCM for my kid's 2000 Durango. Good bet that's what it is. Sorry to say that based on my experience you will try SEVERAL from the people who sell these as "rebuilt" on Ebay before getting one that actually works, and this is assuming that they don't lose your order or lose track of the 3 or 4 bad ones that you return, causing you to have to make a phone call each time. All of this happened to me and with 2 different sellers.
This was probably the worst auto parts experience I have ever had and it caused the truck to be down for weeks.
My guy strongly suggested that I get a genuine Mopar reman. I resisted and resisted, and went through 6, yes 6 of them from the other guys before finally breaking down and going to the dealer (list price 700+). Truck was back on the road without another computer related problem the minute the Mopar one was installed.
I'm trying to sell it now on Ebay since the torque converter is fried so I'm done with the Durango after dropping 2k on this whole computer thing last summer. Sorry to vent and I wish you better luck. BTW these things are said to be very "part number intensive" so I don't think the one I have will work for you, but if-so I'll make you a good deal on it. It is listed now for 400 dollars.
I suggest maybe try 1 from the other guys and hope you get lucky but if that one fails cut your losses right there. Also, some were bad right out of the box
(tested hot&cold?????) and others failed a short time later. My guy claims that for whatever reason the Dodge truck PCM's are all but impossible for the rebuilders to fix correctly, but not so for other vehicles, that's why their feedback is so good.
 
No bus means there is signal communication error(s) between the various control modules. It is a dreaded problem, no question. The problem is usually in the PCM, but can be many other things. You need to find a shop with a proper scanner with a can module or a newer scanner with the can built in. It usually goes well beyond our normal one hour diagnostics on these codes, but sometimes you get lucky and find the problem right away. Unfortunately, I am going to have to recommend an experienced shop or mechanic. It is not something the average Joe can figure out at home, unless he wants to just throw parts at it until it is fixed.
 
I had a 2000 Ram that out of nowhere developed an intermittent "no bus" on the gauge cluster when I hit bumps. The truck would stutter or die when it happened.

I found it to be a group of ground wires bolted to the front of the drivers side cylinder head that the bolt had come loose and the wires were very corroded.

I also heard that most of the time it is caused by a bad PCM, but at least the ground wires are something that can be checked easily.
 
Thanks for helping all!

I have checked ground wire's, fuses, even have the 5 volt reference, pulled the gauge cluster. I'm afraid it's going to be the PCM also...............................
 
As stated earlier. PCM or crank sensor. PCM fixed mine when the crank sensor didn't.
 
Bus lines are almost impossible to trace without a breakout box.Crank and PCM is the most common. But if something else failed it will interfear other signals. Not to get off track but had a customer with a new caddy. Car died because of the radio. It shared the bus line for the PCM. Stupid ****.
 
WRB426 said:
Bus lines are almost impossible to trace without a breakout box.
Click to expand...

Ye olde PCI bus. There is no actual 'code' generated for this issue and is why you see the no bus message on the cluster. The sensor goes out and 'brings down the bus'. I've done enough of them over the years to know.

Pretty sure they're on the right side in an older Ram. Sensor is $55-75 depending where you get one. Its a 15 minute job with a lift, the right extensions and swivel sockets. Otherwise, it can be a *****.

I've had to do it twice in my '01 Cherokee, neither time in a shop - once in my driveway and the other parked in front of a friends house. In my car it's on the left side. You can reach it from the top but its hard to do, much easier from the bottom.
 
You guys are awesome!! I might as well change the crank sensor first, then if it's not that move on to the PCM.
 
alleyoopmgv said:
Thanks for helping all!

I have checked ground wire's, fuses, even have the 5 volt reference, pulled the gauge cluster. I'm afraid it's going to be the PCM also...............................
Click to expand...

You may have already done this, according to the above description, but my 02 Durango died (literally no power to anything) due to a loose connection on the main "hot wire" to the fuse box under the hood. It is the main power feed (I think) into the box and is hard to miss. I am trying to find an image for you.

I had to remove the connector, clean all the surfaces and then put it back on good and tight.
 
Here is the image and the large connection on the left is the one that gave me problems. (The one with the red and black wire cut and hanging there on the left) Might be too much to hope for, but worth a try.
 

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SpikeWills69 said:
Here is the image and the large connection on the left is the one that gave me problems. (The one with the red and black wire cut and hanging there on the left) Might be too much to hope for, but worth a try.
Click to expand...

Thank you SpikeWills69, I have already tried that also, and the connecter under the dash by the e-brake. Thanks for the input!

Thanks to all of you that have replied to my post! I appreciate all of your guys input! Hopefully I can get this thing figured out!?!?
 
alleyoopmgv said:
You guys are awesome!! I might as well change the crank sensor first, then if it's not that move on to the PCM.
Click to expand...

If you want to get into the architecture of it, the crank sensor on a PCI bus is kind of like its own module, even though its 'only' a sensor. If the PCM can't tell how fast the crank is moving or where it is, it can't execute the other commands which are based on crank position/speed.

For communication to happen over the bus circuits, there has to be specific resistance values met based on the termination resistance values of the modules. (PCM, BCM etc. ) Messages (voltage) are sent out and returned. If one of the modules has a short, open etc. the resistance value will be incorrect and thus the voltage values being transmitted (or not) over the bus circuits will be out of range. Hence the 'no bus' message.

If the PCM was 'bad', you would probably see a multitude of other issues. Its rare that replacing a PCM will solve an issue. I'd see guys do it, program it etc., take the car for a ride and find that whatever issue was present before PCM swap is still there. Then they'd hand it off to the 'tough problem' guy and he'd find the wiring issue.

Try to use caution if you plan to mess with anything else. Once you start pulling on wires/connectors you can disturb things and cause other issues or mask the original cause of the problem.
 
Well I finally got around to changing my crank sensor but, no dice. Still didn't start.

Anyone else????
 
Do any of your buddies or family drive a 99 to 2001 ram with a V8? Either 318 or 360? See if they would let you put their PCM in your truck and find out if it starts. It won't hurt anything to try. If it ends up that the PCM fixes it, try your local salvage yard. Usually the PCM is one of the first things pulled at the yard, but you might get lucky! I ended up having to buy one from a local parts house that had been reconditioned.
 
alleyoopmgv said:
Well I finally got around to changing my crank sensor but, no dice. Still didn't start.

Anyone else????
Click to expand...

Really? Huh. Where was the crank sensor?

Start checking fuses under the dash and under the hood. Sometimes a blown fuse can 'bring down the bus'.

If you replace the PCM, you might solve the problem but you may not be solving the initial or real problem. You need a scan tool to replace the PCM.
 
One of the modules is shorting out the buss wich is the communications network for all the modules in the truck you can unplug the modules one at a time to see if the no buss message goes away I have had 2 trucks recently with this same issue both ended up being the pcm. There are companies that repair or rebuild pcm's you send them the old one with the vin and the mileage and they send you back one.

Brian
 
I don't have a reference to a Dodge truck to add here. I'm commenting only because of the vehicles age.
All of the recent repairs I have done were due to faulty ignition switches. ! Town Car, 1 Impala, 1 Prelude, 1 F150. Manually operated switches are the most common circuit faults. Probably always will be.
If you Google the problem and ignition switch doesn't show up, ignore this post.
Good luck
 
Thanks for the replies fella's!

That's a good idea BadAss71!

@rmchrgr, the crank sensor is at the top of the bell housing pas side. Got to it from the top.
 
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