CAN bus Failure

[Dfout]

Update for anyone following:

the Ford dealership it’s at has yet to find anything, and is stating, with lack of evidence, that is is the amount of “accessories” the truck has that has overloaded the CAN bus system.

So I’m not an engineer, but I have worked in off-road shops and do a lot of my own work still, and this makes little sense to me. Everything is properly hooked up and fused, and ford even said themselves that the battery and alternator are good. This Is a list of what is installed, electrically, on the truck:

The following are on a BlueSea fuse block,

Hella Valuefit lights on bumper, LED
Lightforce ditch lights, LED
Rock lights , 6 in total, LED
Tank heater for flatbed water tank (have flatbed canopy that comes off)
ARB LINX module, which monitors every accessory and has low voltage shut off enabled


The following are double fused positive and negative right from the battery, as is proper with a radio instal

Midland GMRS radio, 25W
Yaesu 50w mobile

Does anybody more knowledgeable than I think that any of this could’ve possibly overloaded a system it doesn’t even touch? I understand that everything has to draw power, I just find it really hard to believe that if no fuses were blown, no damage was done to the battery or alternator, that any accessories could have drawn power enough from modules nowhere near them to do harm.

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[P. A. Schilke]

Update for anyone following:

the Ford dealership it’s at has yet to find anything, and is stating, with lack of evidence, that is is the amount of “accessories” the truck has that has overloaded the CAN bus system.

So I’m not an engineer, but I have worked in off-road shops and do a lot of my own work still, and this makes little sense to me. Everything is properly hooked up and fused, and ford even said themselves that the battery and alternator are good. This Is a list of what is installed, electrically, on the truck:

The following are on a BlueSea fuse block,

Hella Valuefit lights on bumper, LED
Lightforce ditch lights, LED
Rock lights , 6 in total, LED
Tank heater for flatbed water tank (have flatbed canopy that comes off)
ARB LINX module, which monitors every accessory and has low voltage shut off enabled


The following are double fused positive and negative right from the battery, as is proper with a radio instal

Midland GMRS radio, 25W
Yaesu 50w mobile

Does anybody more knowledgeable than I think that any of this could’ve possibly overloaded a system it doesn’t even touch? I understand that everything has to draw power, I just find it really hard to believe that if no fuses were blown, no damage was done to the battery or alternator, that any accessories could have drawn power enough from modules nowhere near them to do harm.

Hi anybody is dealing with possible overloaded system, it is Sid or Jack...

best,
Phil

 

[JDowns]

If I'm not mistaken most of those codes are BCM related besides the C### reverse signal (APIM) which gets its status from the BCM.

Are any of your accessories tied into the BCM?

My money would be you have a fried BCM with that many error codes.

 

[Dfout]

If I'm not mistaken most of those codes are BCM related besides the C### reverse signal (APIM) which gets its status from the BCM.

Are any of your accessories tied into the BCM?

My money would be you have a fried BCM with that many error codes.

nothing that I have done is tied to the BCM, or spliced into any of the CAN harnesses or connectors. Only thing that was changed that I can think of is the rear camera was relocated when I did the flatbed swap. It’s an aftermarket camera.

 

[JDowns]

Just looking at the errors you can trace everything related back to a BCM component. Only reason I mention BCM.

I can't see how you have overloaded the CANBUS. Folks on here have a lot more amp draw going on than you do, and CAN is just the communications method that all the controllers talk to each other. So saying a CAN overload sounds like a generic (was going to say "canned") response. So one of the modules is failing and with all the codes pointing to BCM components, I would say BCM.

It's possible everything started with the reverse camera, but would it affect the other circuits is the unknown.

It would be impossible to really tell since there is no known schematic for the BCM. But general parts of the BCM would be the MCU (microcontroller), Interface (CAN, LIN, etc), some sort of protection circuit for the power (battery), eFuses (FET's) for lighting and ancillary devices, load drivers (windows, locks, etc). With your errors the CAN is getting messages about mostly shorts to ground and all related to the rear of the vehicle. I would venture a guess that some hard component in the BCM has failed to have that many circuits failing.

 

[Racket]

Wasn't there a recall on certain builds for the reverse camera?

 

[SteamiestOyster]

Get FORSCAN. Try to read data from every module. If you are getting errors from multiple modules you probably have a wiring problem. There are (iirc) 3 CAN buses on the truck. Hopefully the wiring problem is just on 1 bus. There is also a chance that a 12V wire shorted with a CAN wire and that would cause 12V to potentially damage modules that are only designed to handle low voltage CAN data. Again, that would only be likely if you had errors on 1 bus only. Very unlikely that you had a short on multiple buses. But if your are only seeing errors from one module then it's most likely just the one module that's bad.

Also, what did the dealer actually do to troubleshoot this? I can't imagine they don't have a diagnostic tool to do what I described above automatically. Either that or the technician doing the troubleshooting has no idea what he's doing. Data buses are easy. You either have good data or you don't.

 

[Dfout]

Just looking at the errors you can trace everything related back to a BCM component. Only reason I mention BCM.

I can't see how you have overloaded the CANBUS. Folks on here have a lot more amp draw going on than you do, and CAN is just the communications method that all the controllers talk to each other. So saying a CAN overload sounds like a generic (was going to say "canned") response. So one of the modules is failing and with all the codes pointing to BCM components, I would say BCM.

It's possible everything started with the reverse camera, but would it affect the other circuits is the unknown.

It would be impossible to really tell since there is no known schematic for the BCM. But general parts of the BCM would be the MCU (microcontroller), Interface (CAN, LIN, etc), some sort of protection circuit for the power (battery), eFuses (FET's) for lighting and ancillary devices, load drivers (windows, locks, etc). With your errors the CAN is getting messages about mostly shorts to ground and all related to the rear of the vehicle. I would venture a guess that some hard component in the BCM has failed to have that many circuits failing.

What would be a way of going around to test if the BCM is the culprit in all this? The verbatim response that I got from the service manager, they wouldn’t even let me talk to the techs physically working on it, was that they “ couldn’t get any of the modules to wake up“. I don’t think they physically opened anything up yet and they are being incredibly vague when they are telling me what exactly all they have done. Truck has been in the shop for over 10 days now and they haven’t called me a single time other than me stopping in once. Getting a little frustrated that nothing is going to end up done to it

 

[Dfout]

Get FORSCAN. Try to read data from every module. If you are getting errors from multiple modules you probably have a wiring problem. There are (iirc) 3 CAN buses on the truck. Hopefully the wiring problem is just on 1 bus. There is also a chance that a 12V wire shorted with a CAN wire and that would cause 12V to potentially damage modules that are only designed to handle low voltage CAN data. Again, that would only be likely if you had errors on 1 bus only. Very unlikely that you had a short on multiple buses. But if your are only seeing errors from one module then it's most likely just the one module that's bad.

Also, what did the dealer actually do to troubleshoot this? I can't imagine they don't have a diagnostic tool to do what I described above automatically. Either that or the technician doing the troubleshooting has no idea what he's doing. Data buses are easy. You either have good data or you don't.

So the service Manager there hasn’t even let me talk to a tech yet, which was incredibly annoying. From what I gathered there is multiple modules that are not responding, and I don’t think they are able to read anything off of them. He described it as not being able to wake up the modules, so I’m not sure if they are just not sending any information, or if they’re totally off-line. I guess it’s always possible that some thing that was put on aftermarket electronically could have shorted something out, but all the wiring I do gets shoved in Lume everything is heat wrapped and protected. There is some wiring that the company who installed the flatbed did that was pretty sketchy, but I have since ripped all that out and replaced it. There is nothing that I have done that runs anywhere near the factory wiring harness except going in through a grommet in the firewall under the drivers side foot well. That is all been loomed and stuffed in corrugated plastic.

 

[JDowns]

What would be a way of going around to test if the BCM is the culprit in all this? The verbatim response that I got from the service manager, they wouldn’t even let me talk to the techs physically working on it, was that they “ couldn’t get any of the modules to wake up“. I don’t think they physically opened anything up yet and they are being incredibly vague when they are telling me what exactly all they have done. Truck has been in the shop for over 10 days now and they haven’t called me a single time other than me stopping in once. Getting a little frustrated that nothing is going to end up done to it

Oh man that is incredibly frustrating.

I would only be speculating as I've never seen a schematic of the modules and wiring on these trucks. My world in non automotive revolves around programming, mostly embedded systems, I do have a broad understanding of electronics, enough where I can hook up a o-scope and do diagnostics, re-solder components, etc. I tend to leave the hardware side to others.

But my understanding is that while the BCM has internal fuses (FETs) to monitor and control items like marker lighting, ambient lighting, doors, windows, (etc), it can also serve as a gateway for communications between other modules like the APIM, PCM/ECM, Trailer Brake, and on and on.

So if they can't talk with any of the modules then it sounds like the BCM has failed. Now that is clearly an assumption and there could be another hub/gateway that is the central communications point.

Hopefully they can get it fixed quicker and you can get back to enjoying your ride.

I can understand it being a lot of work going through a service manual and step by step going through test points to determine where a failure is happening to determine a root cause. This is where poor communication can be frustrating. If only the tech could communicate to the manager in simple terms what is being done and the steps that are being taken. Otherwise it seems as though nothing is getting done. But I can also understand from the tech's perspective if he is knee deep in diagnostics not wanting to spend a bunch of time explaining what he is doing to a manager, and just wanting to figure out the problem.

 

[JDowns]

After a bit of searching the BCM is not the hub. Our trucks are equipped with a Smart Data Link Module (Part #14F642). It is located under and within the fuse block.

Here is an informative video on diagnosing the gateway / smart gateway modules and the lengthy steps in diagnosing communication issues.



I can imagine this being a nightmare trying to diagnose the root problem so you don't just replace a module only to have it blow again.

 

[Dfout]

After a bit of searching the BCM is not the hub. Our trucks are equipped with a Smart Data Link Module (Part #14F642). It is located under and within the fuse block.

Here is an informative video on diagnosing the gateway / smart gateway modules and the lengthy steps in diagnosing communication issues.



I can imagine this being a nightmare trying to diagnose the root problem so you don't just replace a module only to have it blow again.

I appreciate the information! Yeah I can’t imagine it’s easy to diagnose at all, I feel bad for the tech working on it but the service manager has not been good. I would tackle it myself but I’m afraid I’m just not that savvy, I could probably struggle through it but I can see myself easily overlooking something due to the fact that I’m just not sure exactly what I’m looking for. The module that is in charge of ford pass connection was the first module to go, about a week before the rear camera, and two before the total shut down. Maybe that’s where it started.

 

[halligan1201]

Electrical issues are the worst. Just ask anyone who ever owned a British car. And while I feel very bad for the OP, these types of threads are half the reason this forum is great - the type of information and experience some of the forum members bring is invaluable, both in their world of expertise and in hearing what resolution was found.

 

[JDowns]

I appreciate the information! Yeah I can’t imagine it’s easy to diagnose at all, I feel bad for the tech working on it but the service manager has not been good. I would tackle it myself but I’m afraid I’m just not that savvy, I could probably struggle through it but I can see myself easily overlooking something due to the fact that I’m just not sure exactly what I’m looking for. The module that is in charge of ford pass connection was the first module to go, about a week before the rear camera, and two before the total shut down. Maybe that’s where it started.

That very well could be and the issue (electrical) just cascaded from there. I'm not sure this could be home done though. Lots of specialized equipment and programs.

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