God forsaken Demon Possessed NO BUS

ItzNickTrash · May 18, 2021

DuRonbo said:
Chrysler made many radio head units that could control CD changers even if the vehicle didn't come with a changer.

With you saying that there's a Violet/Yellow stripe wire taped off behind the aftermarket radio tells me the PCI Bus wire was in the OEM radio wiring bundle at one point.

I'm assuming the original radio wiring connectors were hacked off and some hack job cut and splice was done or?

Is the Metra adapter harness that's in there now already there or was it something you installed?

The original connectors are still there but I've seen pics of the backside of the OEM units and the PCI wire isn't part of the harness. It just goes into a separate hole in the HU, similar to the way that the ground wire is also separate from the harness. Hence the VIOLET/YELLOW wire hanging there all on its own

Christy777 · May 21, 2021

By no means an expert, but my experience with the No Bus on my 2000 5.9; it started shutting down randomly, eventually more frequently. Got to where it would shut down after running 15 mins. Had shop check for codes, tried timing it to when it would die, never got a code-just the No Bus. Would restart after disconnecting neg battery cable. Found a broken bolt on distributor, replaced TPS, one or two other things I don't recall, none of which worked. I finally broke down and bought a PCM from a company on ebay. That was last July, knock on wood, no problems since. Everything I've seen said PCM had to be programmed to your VIN, be the same year, engine type. But I have seen also as you said, if it's the same engine and year it should work. I just got tired of waiting and didn't try out a "loaner" PCM from my shop guy. If none of that other stuff pans out for you, I'd see if there's a way to test your original and junkyard PCM's. Maybe that's why it was in the junkyard, stupid NO Bus code. Good luck!!

TowDurango · May 21, 2021

So the PCM thing:
The rebuilder will take yours as a core and then send you another. You must tell them if you have security or no security. It sounds like you have keyless, so security = Yes.
It's not that they program the PCM to your VIN so much as the PCM is reset on models that have security, so that it will be set to receive the value from your BCM when installed and powered, which is in the cluster. Once "programmed" in this way, the PCM and BCM are linked together. This is why the dealers will say that you need to buy a new PCM, rather than pulling one from a junkyard. The VIN is also used by the rebuilder to make sure that they send the correct calibration for your engine size.

ItzNickTrash · May 22, 2021

Alright so riddle me this, if the PCM is the problem if I were to put another one in that didn't work either because of the security thing or because its not quite the exact same part number would I continue to just get the same NO BUS crank no start problem? Or would it throw a different code with the new/bad PCM?

ItzNickTrash · May 22, 2021

DuRonbo said:
You really need to access a wiring diagram for your year Durango for the OEM wire colors and what they relate to in the Audio system. I don't have that specific info. I'm just providing generic info for several Chrysler vehicles that share the same wiring and functions. I'm sure you can get the Durango wiring info online somewhere free.

I did find the original wiring diagram for both my specific truck as well as the specific heat units the only problem is that the OEM wires don't match the harness which also doesn't match the HU so it is a cluster fuck to sort out

ItzNickTrash · May 27, 2021

Ok so I finally got ahold of the computer out of my buddy's truck his is a 2000 R/T mines a 2001 R/T my PCM # is P56040526AC and the one off his is P56028470AB but we've got all the same options, engine, all that. I can't find anywhere online that says what PCM part #'s might be interchangable. At the very least I'm pretty confident it shouldn't fuck up anything any further. Wish me luck and let me know if y'all know anything I don't related to this whole thing.

ItzNickTrash · May 29, 2021

No dice with the other computer. So I start running down wires, tore apart the whole dash checked all the harnesses at the PCM. Discovered that the factory amp that was supposed to be in the passenger side kicker panel was not there and there was just a bunch of fucking wires hang in there. So I take those off, went to start it, and somehow the battery had gotten drained. So I jumped it with my other truck and boom shakalaka runs idles everything looks good. I get out and go look and then there's some liquid flying around, it ends up being coolant so I go get some stop leak. Pour that in run the engine for 15 minutes no more leak. That was last night, today I hop in go to start it and it cranks starts turns over and then dies almost immediately. So I pop the negative cable to reset the computer again put it back on and she's running like a dream. Decided to go for a test run make it about two blocks and start to break for a red light cuts off, and I get the god damned NO BUS again. Sitting here waiting for my brother to show up with my other truck to tow it a couple blocks back to my house but I've reset the computer a couple of times jiggled wires all over still NO BUS.... I'm really starting to lose motivation to keep at this. Shit is infuriating

Tin Foil Hat · May 29, 2021

It's teasing you because of the stop leak.

ItzNickTrash · May 29, 2021

Okay so sit there wait 10 minutes turn it on to put it in neutral and push it down the way a little bit and I realized that it's not giving me the no bus anymore. Turn it over and starts up idle's fine put it in drive make a u-turn as soon as I get over like 10 miles an hour cuts off, no bus. Wait 10 minutes start her up and get her home just keeping it just above idle. Get home turn it off hold the odometer button and turn it on and I get the 950 code which I guess is for the speed sensor, which makes sense sort of. But why the hell does it no bus me again after cutting off due to the speed sensor, but then ten min later start right up again... Regardless I guess this is progress....

ItzNickTrash · May 30, 2021

Also forgot to mention that ABS light is on... I've seen a bunch of posts about the speed sensor problems from both the one on the t case and the other coupled with the abs on the wheel.

However none of these mention anything about the truck dieing at basically any speed above idle. Closest thing I've seen has been someone talking about it stalling out while turning/braking and how if he threw it in N it would save it from the stall and therefore was speculating that something was up with the sensor on the tranny that was effecting the speed sensor and trans fluids movement causing something to not be able to adjust for the change in load on the engine... I think that's about what they said, honestly all the tranny stuff is over my head.

For now I'm gonna go check/replace if need be the speed sensors starting with the rear wheel hub I suppose. Any ideas are still more than welcome.

ItzNickTrash · May 30, 2021

Hey soooo searched high and low and can't find a for sure answer. Where is the rear abs speed sensor on this beast. (2001 Durango R/t, so 4x4 5.9) is it on the housing or in the wheel hub and if so which wheel?

ItzNickTrash · Jul 26, 2021

So have only had little bits of time here and there to continue this epically elusive problem. As it stands now anytime there truck has been sitting for any period of time beyond 1/2 hour it's starts, isles, ribs, all day lights work, no codes, no CEL. I have twice taken it about 1 mile down the road to the car wash. I get there, turn it off, spend 15-20 min cleaning her up. When I go to leave, she turns right back on no problem. Both on the way there and again on the way back I am, gassing it, breaking hard, cutting turns, just trying to put it through all the motions to see if the issue returns with any correlation to the driving conditions, no dice there though. The first time I made it probably 3/4 of the mile back to my place and just all of a sudden while cruising at speed it just dies, all dash lights blink and then dreaded NO BUS rears its ugly head again. The 2nd time I made this same run I got all the way home and then maybe an hour later fort back in the truck and got about 2 blocks away before the same sudden stall, dash lights blink, NO BUS. On both occasions, after the sudden failure I cannot get it to start and get the NO BUS no matter what I do (disconnect negative battery terminal, unplug and replug connections at ecm and check connections at all of the modules on that same 5v line that I can easily reach). Finally if I just sit and leaves it be for at the Very least 10 min, probably more like 15, she just started up turns right over and plods on down the road without issue. Until something like 20 -25 min of driver time later when we repeat the whole process again... Also as far as I can tell the truck is warmer up to temperature for a significant amount of time before it fails again that and just the feel ive gotten for the whole situation makes me feel fairly confident that the engine temp is at least not the direct cause determining when the failure occurs. If I'm missing something there though I'd be glad to hear it.

I've also tried all the tricks I read about pushin on both the actual casing of the pcm as well as the connectors, Ive cleaned it all thoroughly with contact cleaner and even added a dab of dialectic grease to the connections. No change at all throughout or post that process.

So that's where I stand now, with probably the last idea of where to go from here that I've had since this whole thing started...

The one thought I had was that I noticed a trailer brake that's been installed under my dash, it lights up when ya push the button but I haven't tested it beyond that really.... Any chance that thing might play any role here?

Also, will this thread still get seen by people being 2 months old if I just add a comment like this? Or should I make a new thread to be sure that I'm getting eyes on my issues here?

I'm wide open to any and all ideas, thoughts, or actions that occur to anyone that have any minute possibility of shedding some light on wtf the source of my problem here is.

i really love this truck, it's in such fantastic shape other than this stupid fucking whatever it is. I will be seriously heartbroken if something so seemingly trivial as a pcm communication error keeps me from ever getting her on the road.

Cmonnnn guys, who's got that one bit of divine insight that can extinguish whatever infernal curse I'm dealing with here lol

GTSDart340 · Jul 26, 2021

ItzNickTrash said:
So have only had little bits of time here and there to continue this epically elusive problem. As it stands now anytime there truck has been sitting for any period of time beyond 1/2 hour it's starts, isles, ribs, all day lights work, no codes, no CEL. I have twice taken it about 1 mile down the road to the car wash. I get there, turn it off, spend 15-20 min cleaning her up. When I go to leave, she turns right back on no problem. Both on the way there and again on the way back I am, gassing it, breaking hard, cutting turns, just trying to put it through all the motions to see if the issue returns with any correlation to the driving conditions, no dice there though. The first time I made it probably 3/4 of the mile back to my place and just all of a sudden while cruising at speed it just dies, all dash lights blink and then dreaded NO BUS rears its ugly head again. The 2nd time I made this same run I got all the way home and then maybe an hour later fort back in the truck and got about 2 blocks away before the same sudden stall, dash lights blink, NO BUS. On both occasions, after the sudden failure I cannot get it to start and get the NO BUS no matter what I do (disconnect negative battery terminal, unplug and replug connections at ecm and check connections at all of the modules on that same 5v line that I can easily reach). Finally if I just sit and leaves it be for at the Very least 10 min, probably more like 15, she just started up turns right over and plods on down the road without issue. Until something like 20 -25 min of driver time later when we repeat the whole process again... Also as far as I can tell the truck is warmer up to temperature for a significant amount of time before it fails again that and just the feel ive gotten for the whole situation makes me feel fairly confident that the engine temp is at least not the direct cause determining when the failure occurs. If I'm missing something there though I'd be glad to hear it.

I've also tried all the tricks I read about pushin on both the actual casing of the pcm as well as the connectors, Ive cleaned it all thoroughly with contact cleaner and even added a dab of dialectic grease to the connections. No change at all throughout or post that process.

So that's where I stand now, with probably the last idea of where to go from here that I've had since this whole thing started...

The one thought I had was that I noticed a trailer brake that's been installed under my dash, it lights up when ya push the button but I haven't tested it beyond that really.... Any chance that thing might play any role here?

Also, will this thread still get seen by people being 2 months old if I just add a comment like this? Or should I make a new thread to be sure that I'm getting eyes on my issues here?

I'm wide open to any and all ideas, thoughts, or actions that occur to anyone that have any minute possibility of shedding some light on wtf the source of my problem here is.

i really love this truck, it's in such fantastic shape other than this stupid fucking whatever it is. I will be seriously heartbroken if something so seemingly trivial as a pcm communication error keeps me from ever getting her on the road.

Cmonnnn guys, who's got that one bit of divine insight that can extinguish whatever infernal curse I'm dealing with here lol

I'm no wiring expert, but if that trailer controller was wired incorrectly it's possible it could be causing problems. Unplug it and see what happens.

1949 International KB2, 302/T5
1968 Dodge Dart GTS, 340/727
2006 Dodge Magnum R/T "SRT Design"
2016 Dodge Durango Limited

ItzNickTrash · Aug 10, 2021

PROGRESS but not quite there.

So after letting it sit for a week or so I couldn't even get it to start up at all anymore, it was just the NO BUS right off the bat. UNTIL!

i found this thread: Fixing a Dakota/Durango "nO bUS" PCM for under $5! - DodgeForum.com <----- TLDR: splice in a phone charger rated for 5v to stand in for the PCM 5v Output to provide power to the relative modules due to the PCM not putting out sufficient voltage on its own.

so followed their logic, tested the wire. saw the voltage drop. spliced in an alternative 5v power supply (though my pin 17 5v output wire was orange) and SUCESS! she starts she runs, i let her idle in my driveway for a full 45 min no problem. Go to take her for a ride and make it maybe ten min down the road and the same old story yet again gauges dead, cluster lights everywhere NO BUS crank no start. Pop the hood and do whatever i can to cool off the PCM (fanning it mostly) and after just a few min (once its not feeling warm to the touch anymore) she fires right back up no problem. At this point i realize that it idled in my driveway as long as it did because i didnt shut the hood facepalm

so seeing as i solved the 5v output problem by installing an alternative source of power just after the harness (right where he does in the thread i linked) yet heat is still somehow causing me to get the same results as before what do ya fancy the heat is doing exactly and to what? Is it still the PCM somehow/for some reason? if so, if i were to splice in longer wires and move it into my cab might that be likely to solve it? or is the heat effecting something else down the line that im missing?

Not sure if relevant as i never had any reason to think that it was related to this problem but just to be thorough my A/C doesn't seem to blow at all, not hot or cold.

Lastly, when i pop the hood after running for a while and catching the NO BUS it feels a bit warmer than my instincts say it should be. My temp gauge seems to work fine and it doesn't register as being abnormally hot at all... Does anyone know how hot is too hot if i was to just stick a thermometer under the hood to get an idea of the ambient temp under there?

I know im so close to having this sorted out, i can feel it! I just gotta get through this last stretch!

::UPDATE:: Also probably unrelated but went to just take it for a real quick ride down the road and as im trying to parellel park it stalls but starts right back up but ever since then i have absolutely no power steering at all.. I dont really hear anything when trying to turn the wheel (like the whines and groans typically encountered with a bad pump) but ive taken it around the block a couple times since then and there's still NO help turning that wheel at all. Only noise i did notice was last night when i had it running with hood up (which it will do endlessly as long as the hoods up) somewhere on the drivers side somewhere towards the bottom of the engine compartment and between the firewall and junction box area theres a pretty fast clicking sound. I didn't get a chance to investigate it much further than that just yet but just in the spirit of putting it all out there thought id mention that too.
Like I mentioned earlier in this thread i basically have a full parts truck at my disposal so if it comes down to having to replace the PS pump or the rack and pinion, either way is not the end of the world really.

I just absolutely have to get this NO BUS thing fully fixed for my own sanity if not for just the practicality of being able to to drive the truck.

thanks for everyone's input so far and looking forward to anything else ya got for me

GTSDart340 · Aug 10, 2021

ItzNickTrash said:
PROGRESS but not quite there.

So after letting it sit for a week or so I couldn't even get it to start up at all anymore, it was just the NO BUS right off the bat. UNTIL!

i found this thread: Fixing a Dakota/Durango "nO bUS" PCM for under $5! - DodgeForum.com B]

so followed their logic, tested the wire. saw the voltage drop. spliced in an alternative 5v power supply (though my pin 17 5v output wire was orange) and SUCESS! she starts she runs, i let her idle in my driveway for a full 45 min no problem. Go to take her for a ride and make it maybe ten min down the road and the same old story yet again gauges dead, cluster lights everywhere NO BUS crank no start. Pop the hood and do whatever i can to cool off the PCM (fanning it mostly) and after just a few min (once its not feeling warm to the touch anymore) she fires right back up no problem. At this point i realize that it idled in my driveway as long as it did because i didnt shut the hood facepalm

so seeing as i solved the 5v output problem by installing an alternative source of power just after the harness (right where he does in the thread i linked) yet heat is still somehow causing me to get the same results as before what do ya fancy the heat is doing exactly and to what? Is it still the PCM somehow/for some reason? if so, if i were to splice in longer wires and move it into my cab might that be likely to solve it? or is the heat effecting something else down the line that im missing?

Not sure if relevant as i never had any reason to think that it was related to this problem but just to be thorough my A/C doesn't seem to blow at all, not hot or cold.

Lastly, when i pop the hood after running for a while and catching the NO BUS it feels a bit warmer than my instincts say it should be. My temp gauge seems to work fine and it doesn't register as being abnormally hot at all... Does anyone know how hot is too hot if i was to just stick a thermometer under the hood to get an idea of the ambient temp under there?

I know im so close to having this sorted out, i can feel it! I just gotta get through this last stretch!

::UPDATE:: Also probably unrelated but went to just take it for a real quick ride down the road and as im trying to parellel park it stalls but starts right back up but ever since then i have absolutely no power steering at all.. I dont really hear anything when trying to turn the wheel (like the whines and groans typically encountered with a bad pump) but ive taken it around the block a couple times since then and there's still NO help turning that wheel at all. Only noise i did notice was last night when i had it running with hood up (which it will do endlessly as long as the hoods up) somewhere on the drivers side somewhere towards the bottom of the engine compartment and between the firewall and junction box area theres a pretty fast clicking sound. I didn't get a chance to investigate it much further than that just yet but just in the spirit of putting it all out there thought id mention that too.
Like I mentioned earlier in this thread i basically have a full parts truck at my disposal so if it comes down to having to replace the PS pump or the rack and pinion, either way is not the end of the world really.

I just absolutely have to get this NO BUS thing fully fixed for my own sanity if not for just the practicality of being able to to drive the truck.

thanks for everyone's input so far and looking forward to anything else ya got for me

I'm not sure on the wiring, but if the engine isn't spewing coolant then the engine isn't overheating. The engine compartment will be hot, that's the nature of internal combustion. As far as the no steering assist, make sure the belt is still on. The power steering is not electronically controlled, so that would mean a broken/slipping belt, bad pump or low fluid would be the likely culprit. It could be a bad rack and pinion, but that's less likely.

1949 International KB2, 302/T5
1968 Dodge Dart GTS, 340/727
2006 Dodge Magnum R/T "SRT Design"
2016 Dodge Durango Limited

TowDurango · Oct 1, 2021

On my 99 Durango, when the PCM was bad, I could drive as long as a 1 gallon zip lock bag full of ice on the PCM stayed cold. This sort of behavior in electronics typically indicates a bad connection. It can be an internal bond wire or a cold solder joint. This is a sure sign that a replacement PCM is required.

That 5 volt test is really ingenious. The 5 volt line is called the VREF (voltage reference). It is very tightly regulated to as close as possible to 5v; like 4.97 to 5.03. This is because it's used as the sensor voltage feed for most of the car's sensors. The sensor output of some sensors varies based on the voltage input, so a really well regulated voltage on VREF is essential. NO BUS just means that the vehicles modules can't intercommunicate. It's usually not the wiring (two wires IIRC), but rather an issue with the modules themselves. Since the NO BUS prevents a scanner from working, it's a goldmine for the dealer. In reality, they already know that the PCMs on 98-03 Durangos are a 100% failure item; it's just a matter of time (or rather heat).

felix.oclair · Feb 9, 2023

Did you ever figure it out? I have same issue.. Very frustrating.

Ike03 · Feb 9, 2023

I actually read this thread. But for the grace of God there go I

mhudgens800 · Nov 5, 2024

Car Computer exchange out of Raleigh NC fixed this problem.... when you get your new electronic control module.... don't hook up pos or neg terminals let it die for 24hrs... only hook up the module itself let it set for 12hrs with plugs on the module...then put key in door lock like u are unlocking the car cycle through lock and unlock several times...then put key in ignition to crank.. good luck 🤞

God forsaken Demon Possessed NO BUS

ItzNickTrash

Christy777

TowDurango

ItzNickTrash

ItzNickTrash

ItzNickTrash

ItzNickTrash

Tin Foil Hat

ItzNickTrash

ItzNickTrash

ItzNickTrash

ItzNickTrash

GTSDart340

ItzNickTrash

GTSDart340

TowDurango

felix.oclair

Ike03

mhudgens800

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