Hello all. I’ve been reading every forum I can find for answers to my seemingly unique No Bus Problem. I have a late model 2002 Durango with the newer NGC Pcm. When I have this message, It starts and runs perfectly. I’ve driven it well over 100 miles at once with gauge’s not working, annoying beeping and all. One thing that is a constant is that it’s very dependent on the temperature outside. When it’s below 50 degrees everything functions as it should. Once I drive it and it warms up I’ll get No Bus as soon as I shut it down and restart. If it’s hot outside, I’ll have a No Bus from the minute I start it. I’m just pulling my hair out because I need to get it smogged and it won’t pass in this condition. I cannot find one other posting of somebody with this same problem. Everyone else seems to have a stalls out won’t start problem with the no bus. Please, is there anybody else out there in my boat?
dlazzarini
. . . I think I remember reading once that the NOBUS message on the odometer meant that somewhere on the PCI Bus there was a communication break down between the modules. The Mechanical Instrument Cluster (MIC) is actually one of the modules on the PCI Bus, and I think that maybe the NOBUS message actually means that the communication break down is there with the MIC (but I am not completely sure about that part). Depending on how the Dakota is equipped, the 2003 (Dakota) FSM is showing up to 12 modules on the PCI Bus which communicate with each other, and this includes the PCM as one of those modules.
If I was actually correct that the NOBUS message pertains specifically to the MIC, I think that there is a self-test that can be ran on the cluster, & you might give that a try when it is in the NOBUS mode. Taking that theory one step further, it seems as if the problem could be with the the MIC (cluster) connection point, or with the cluster itself, and increase in temperature exaserbates it. That is just a shot in the dark, however, and I don't know how one would go about checking that, except trying the self test and seeing if/or what codes come up, or swapping out the cluster, which probably is not a part most people would choose to shotgun with.
If I was actually correct that the NOBUS message pertains specifically to the MIC, I think that there is a self-test that can be ran on the cluster, & you might give that a try when it is in the NOBUS mode. Taking that theory one step further, it seems as if the problem could be with the the MIC (cluster) connection point, or with the cluster itself, and increase in temperature exaserbates it. That is just a shot in the dark, however, and I don't know how one would go about checking that, except trying the self test and seeing if/or what codes come up, or swapping out the cluster, which probably is not a part most people would choose to shotgun with.
No sweat, I'll take a look and see if I can find the test for the cluster.
As far as getting it smogged, though, you might call the inspection station first and tell them you have a NOBUS on your odometer and see if that will effect them doing the emissions.
I was thinking it might not, because as long as they still could establish a connection between their computer and your PCM, I was thinking that they should be able to read the codes and whether you were a pass or a fail.
But I am not sure about that.
As far as getting it smogged, though, you might call the inspection station first and tell them you have a NOBUS on your odometer and see if that will effect them doing the emissions.
I was thinking it might not, because as long as they still could establish a connection between their computer and your PCM, I was thinking that they should be able to read the codes and whether you were a pass or a fail.
But I am not sure about that.
. . . I did find a thread that I previously replied to; in that thread a gauge indication problem was described and I typed out the test for the cluster. Now I am not sure that this is going to work for you, as I am thinking that when you are in the NOBUS mode, nothing at all on the cluster is going to function, not even the test, BUT, MAYBE it will give you a 3 digit code, and if it does, and you get back to us and post what it is, I will look it up for you.
This is from an '03 Dak FSM, but I am thinking that this part should be the same. I type poorly & slowly, so when I originally typed this up I did some paraphrasing & condensing, so if anything doesn't make sense to you, let me know & I'll look back at the FSM & spell out the detail verbatim.
This is the cluster test that I am pasting for you:
Okay, with the rules of paraphrasing & condensing that I listed above, the actuator test puts the cluster into a self diagnostic mode.
Successful completion of test confirms that the cluster works, but there still may be a problem with the PCI bus, the PCM, the CTM (Central Timer Module) the transmission control module (TCM), transfer case control module ((TCCM) , Airbag control module (ACM), the CAB (basically the ABS module), or inputs to one of these modules. The FSM tells you to use a DRBIII scan tool to diagnose these components.
Okay, first off there is a large warning paragraph in bolds warning you of the dangers of screwing with your steering wheel etc related to setting your airbags off. For now, I believe this is not applicable. If it looks like it is, I will come back to it.
1)put ignition switch to OFF
2)depress odometer/trip meter switch button
3)while holding trip meter switch button depressed, turn key to ON but do not start engine
4)keep trip meter switch button depressed for about 10 seconds until CHEC appears on odometer display then release.
5)a series of 3 digit numeric failure messages may appear in the odometer depending upon failure mode.
(If you get one of these, post it & I will get back to you & let you know what it is.)
6)instrument cluster will begin the vacuum fluorescent display (VFD) walking segment test. W#e can skip that for now except to say that it involves the "segements" illuminating in a sequence. As I typed, we can come back to that if need be.
7)cluster will perform a bulb check. I thyink we can skip that for now, also, but if need be we can get back to it.
8)gauge actuator test: cluster circuitry positions each gauge needle a 3 different calibration points then returns them to their relaxed positions. If an individual gauge does not respond properly or does not respond at all, the cluster should be removed.
(This might be where the warnings in bold that I previously alluded to come into play.)
However, check that the spring clip terminal pin receptacles on the cluster electronic circuit board before considering cluster replacement. If gauge terminal connections are okay, replace the faulty instrument cluster.
9)actuator test now complete. Cluster will automatically exit self diagnostic mode & return to normal operation, at the completion of test, if the ign switch is turned to OFF during test, or if a vehicle speed message indicating that vehicle is moving is received from the PCM on the PCI data bus during the test.
10)repeat as needed.
This is from an '03 Dak FSM, but I am thinking that this part should be the same. I type poorly & slowly, so when I originally typed this up I did some paraphrasing & condensing, so if anything doesn't make sense to you, let me know & I'll look back at the FSM & spell out the detail verbatim.
This is the cluster test that I am pasting for you:
Okay, with the rules of paraphrasing & condensing that I listed above, the actuator test puts the cluster into a self diagnostic mode.
Successful completion of test confirms that the cluster works, but there still may be a problem with the PCI bus, the PCM, the CTM (Central Timer Module) the transmission control module (TCM), transfer case control module ((TCCM) , Airbag control module (ACM), the CAB (basically the ABS module), or inputs to one of these modules. The FSM tells you to use a DRBIII scan tool to diagnose these components.
Okay, first off there is a large warning paragraph in bolds warning you of the dangers of screwing with your steering wheel etc related to setting your airbags off. For now, I believe this is not applicable. If it looks like it is, I will come back to it.
1)put ignition switch to OFF
2)depress odometer/trip meter switch button
3)while holding trip meter switch button depressed, turn key to ON but do not start engine
4)keep trip meter switch button depressed for about 10 seconds until CHEC appears on odometer display then release.
5)a series of 3 digit numeric failure messages may appear in the odometer depending upon failure mode.
(If you get one of these, post it & I will get back to you & let you know what it is.)
6)instrument cluster will begin the vacuum fluorescent display (VFD) walking segment test. W#e can skip that for now except to say that it involves the "segements" illuminating in a sequence. As I typed, we can come back to that if need be.
7)cluster will perform a bulb check. I thyink we can skip that for now, also, but if need be we can get back to it.
8)gauge actuator test: cluster circuitry positions each gauge needle a 3 different calibration points then returns them to their relaxed positions. If an individual gauge does not respond properly or does not respond at all, the cluster should be removed.
(This might be where the warnings in bold that I previously alluded to come into play.)
However, check that the spring clip terminal pin receptacles on the cluster electronic circuit board before considering cluster replacement. If gauge terminal connections are okay, replace the faulty instrument cluster.
9)actuator test now complete. Cluster will automatically exit self diagnostic mode & return to normal operation, at the completion of test, if the ign switch is turned to OFF during test, or if a vehicle speed message indicating that vehicle is moving is received from the PCM on the PCI data bus during the test.
10)repeat as needed.
. . . I've read quite a few NOBUS threads (usually with a crank but no start scenario attached to them) and I've never read a great explanation or troubleshooting sequence. It comes off as a complex and mysterious condition.
But here is another example of something that makes me THINK that NOBUS on the odometer pertains to a breakdown in communication between the cluster and something else (could be another module) on the PCI bus. If, for example, there was a screw up with just your CAB module (controller antilock brake) you would NOT get a NOBUS, but you would get a red 'brake' light & probably an 'ABS' light. The same with your ABS module--an ABS light but NOT a NOBUS light. (Even though both of these conditions constitute a failure on the PCI Bus.) That's why I am thinking the NOBUS on the odometer is notifying the user that the PCI bus problem includes the cluster module, but not necessarily anything else..
Which is not to say that the NOBUS condition might not also include, as an example, something with the PCM (another module on the PCI bus) and therefore a condition where the engine won't start.
But if my NOBUS theory is correct, in your application that last scenario is not the case. It seems obvious that whatever is going on is electrical, and I suppose it could be a resistance change somewhere in the wiring or a connector that happens when the temperature of that (whatever it is) rises to a certain point. And of course, that is just another shot in the dark, but for right now, it's the best I can think of.
But here is another example of something that makes me THINK that NOBUS on the odometer pertains to a breakdown in communication between the cluster and something else (could be another module) on the PCI bus. If, for example, there was a screw up with just your CAB module (controller antilock brake) you would NOT get a NOBUS, but you would get a red 'brake' light & probably an 'ABS' light. The same with your ABS module--an ABS light but NOT a NOBUS light. (Even though both of these conditions constitute a failure on the PCI Bus.) That's why I am thinking the NOBUS on the odometer is notifying the user that the PCI bus problem includes the cluster module, but not necessarily anything else..
Which is not to say that the NOBUS condition might not also include, as an example, something with the PCM (another module on the PCI bus) and therefore a condition where the engine won't start.
But if my NOBUS theory is correct, in your application that last scenario is not the case. It seems obvious that whatever is going on is electrical, and I suppose it could be a resistance change somewhere in the wiring or a connector that happens when the temperature of that (whatever it is) rises to a certain point. And of course, that is just another shot in the dark, but for right now, it's the best I can think of.
Just a few more thoughts on this:
first, is there any chance you can get it smogged while the weather is cold? That way, even if you can't figure out or fix your NOBUS at least you could get a sticker on the windshield for another year. . . .
I got into the '03 Dakota Body Diagnostic Procedures (which is mostly related to the PCI Bus) and after that I am somewhat questioning my theory that the inspection station will be able to smog it while it is giving you the NOBUS. Referring to the schematic for the PCI Bus, the Data Link Connector (DLC) is on this Bus (that should have been a no-brainer for me, but I really don't have a lot of understanding about this system and every time I do some reading I learn something I didn't understand before). Anyway, the DLC is the port the scanner hooks up to, and via the PCI Bus it (the DLC) can communicate and read all the other modules which are on the PCI Bus, including, of course, the PCM.
So where I was going with that is: it seems possible to me (I am just guessing again) that the fault that is happening on the PCI Bus could conceivably interfere with the communication between the DLC and the PCM, meaning that the inspection station may not be able to access the emissions data on your PCM.
But I don't know about that. It also seems possible that if my theory about the NOBUS meaning the PCI Bus fault is at your MIC, maybe they can. But if you could get it smogged when you didn't have a NOBUS going on, you wouldn't have to worry about it.
So as I typed, I got into the book last night, and they list all sorts of conditions and the troubleshooting for them, but NONE of what I found (so far) that was listed included the NOBUS message (which seems odd, as from what I have read on these Dakota/Durango sites, NOBUS is not completely uncommon).
Almost ALL of the diagnostic procedures for almost ALL of the listed PCI Bus issues start with using a "DRBIII" scanner at the DLC to read codes after selecting (on the scanner) which module you are trying to communicate with, and apparently ALL the modules on the PCI Bus are capable of storing diagnostic codes that the scanner can pick up from the DLC port. (Which makes me think that you probably would still be able to get it smogged with a NOBUS showing.) I don't think that this could be done with the average scanner that they use at Advance or Autozone, but it does seems as if you could find a facility that does have such a scanner, they might be able to pull a code from whatever on the PCI Bus is causing the fault and NOBUS message.
first, is there any chance you can get it smogged while the weather is cold? That way, even if you can't figure out or fix your NOBUS at least you could get a sticker on the windshield for another year. . . .
I got into the '03 Dakota Body Diagnostic Procedures (which is mostly related to the PCI Bus) and after that I am somewhat questioning my theory that the inspection station will be able to smog it while it is giving you the NOBUS. Referring to the schematic for the PCI Bus, the Data Link Connector (DLC) is on this Bus (that should have been a no-brainer for me, but I really don't have a lot of understanding about this system and every time I do some reading I learn something I didn't understand before). Anyway, the DLC is the port the scanner hooks up to, and via the PCI Bus it (the DLC) can communicate and read all the other modules which are on the PCI Bus, including, of course, the PCM.
So where I was going with that is: it seems possible to me (I am just guessing again) that the fault that is happening on the PCI Bus could conceivably interfere with the communication between the DLC and the PCM, meaning that the inspection station may not be able to access the emissions data on your PCM.
But I don't know about that. It also seems possible that if my theory about the NOBUS meaning the PCI Bus fault is at your MIC, maybe they can. But if you could get it smogged when you didn't have a NOBUS going on, you wouldn't have to worry about it.
So as I typed, I got into the book last night, and they list all sorts of conditions and the troubleshooting for them, but NONE of what I found (so far) that was listed included the NOBUS message (which seems odd, as from what I have read on these Dakota/Durango sites, NOBUS is not completely uncommon).
Almost ALL of the diagnostic procedures for almost ALL of the listed PCI Bus issues start with using a "DRBIII" scanner at the DLC to read codes after selecting (on the scanner) which module you are trying to communicate with, and apparently ALL the modules on the PCI Bus are capable of storing diagnostic codes that the scanner can pick up from the DLC port. (Which makes me think that you probably would still be able to get it smogged with a NOBUS showing.) I don't think that this could be done with the average scanner that they use at Advance or Autozone, but it does seems as if you could find a facility that does have such a scanner, they might be able to pull a code from whatever on the PCI Bus is causing the fault and NOBUS message.
Good luck with replacing the MIC and let us know how it goes and happy holidays to you also.
As far as that code related to the EVAP system, from what I read on the Dak/Durango sites, that doesn't seem to be unusual either. I got my Dak in '14 and it was showing that code and I wound up replacing every piece of vacuum hose under the hood related to it. (That would include from the purge control solenoid and from manifold vacuum.) That particular CEL takes forever to go out by itself and I don't have a scanner so I would unhook the - battt cable and finally it stayed out . . . for about a year. And then, wtf? But I found a little piece that fits on the ports on the purge solenoid that two vacuum lines for the system hook to, and THAT was leaking. (So there is the purge solenoid ports, a small adapter piece, then the two hoses.) I removed that & ran the hoses straight to the ports and the light has stayed out for several years so far.
And here is a trick a guy at an inspection station showed me, and depending upon the rules in your state, it may or may not work. Forgive the lack of technical jargon here, but when the battery is unhooked and "all the computers need to be reset" (?) to read the emissions data, it was explained to me that there are several resets that ultimately happen (let's just say 10 for the sake of this explanation) here in Pa. the emissions can be done if 9 of the 10 resets have happened. And, the EVAP is the last one to reset . . . so . . . that's how I got my Dak through the first emissions after I got it.
As far as that code related to the EVAP system, from what I read on the Dak/Durango sites, that doesn't seem to be unusual either. I got my Dak in '14 and it was showing that code and I wound up replacing every piece of vacuum hose under the hood related to it. (That would include from the purge control solenoid and from manifold vacuum.) That particular CEL takes forever to go out by itself and I don't have a scanner so I would unhook the - battt cable and finally it stayed out . . . for about a year. And then, wtf? But I found a little piece that fits on the ports on the purge solenoid that two vacuum lines for the system hook to, and THAT was leaking. (So there is the purge solenoid ports, a small adapter piece, then the two hoses.) I removed that & ran the hoses straight to the ports and the light has stayed out for several years so far.
And here is a trick a guy at an inspection station showed me, and depending upon the rules in your state, it may or may not work. Forgive the lack of technical jargon here, but when the battery is unhooked and "all the computers need to be reset" (?) to read the emissions data, it was explained to me that there are several resets that ultimately happen (let's just say 10 for the sake of this explanation) here in Pa. the emissions can be done if 9 of the 10 resets have happened. And, the EVAP is the last one to reset . . . so . . . that's how I got my Dak through the first emissions after I got it.
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