Wild Electrical issues fixed

[Vulpes]

My truck is at the dealer currently with some of these same symptoms. No bus, all kinds of service systems warnings, engine running with loss of certain electrical functions and gauges but truck still drives normal until it cuts off while driving after 5-6 minutes.

It really could be anything, for instance the module that controls a door lock inside the door can malfunction and make the whole CAN very angry. Keep us updated on any fixes.

 

[6of36]

These issues can be terribly difficult to diagnose. As an example here is a schematic of just the grounds, every ground is a potential issue. Hope you get yours resolved and share a fix here.

View attachment 162279

30 ground points?! That's wild. Any one can cause electrical problems elsewhere.

 

[ramdude2023]

Another update with my truck..I think I figured it all out. I tested something out this morning and I successfully got it to mess up on command. It’s my passenger seat. A little bit of pressure on my passenger seat messes the truck all up. Obviously I have to figure out why the seat is causing me fits yet, but I’m very pleased that I’ve at least narrowed it down. Anyone have any clue as to why the seat would be causing these issues?

 

[HSKR R/T]

Another update with my truck..I think I figured it all out. I tested something out this morning and I successfully got it to mess up on command. It’s my passenger seat. A little bit of pressure on my passenger seat messes the truck all up. Obviously I have to figure out why the seat is causing me fits yet, but I’m very pleased that I’ve at least narrowed it down. Anyone have any clue as to why the seat would be causing these issues?

Weight sensor in the seat for airbag control. Probably works in canbus

 

[ramdude2023]

Weight sensor in the seat for airbag control. Probably works in canbus

Thanks for the reply. Probably something I’ll have to have dealership take care of I’d assume? Can’t seem to find much on the internet about similar problems with my sensor for guidance.

 

[6of36]

Thanks for the reply. Probably something I’ll have to have dealership take care of I’d assume? Can’t seem to find much on the internet about similar problems with my sensor for guidance.

Yeah, best to let them do something that could effect air bags.

 

[djevox]

These issues can be terribly difficult to diagnose. As an example here is a schematic of just the grounds, every ground is a potential issue. Hope you get yours resolved and share a fix here.

View attachment 162279

The auto repair industry has been dealing with stuff like this for a few decades, so good techs are well adept at dealing with chasing grounds. I even cut my teeth in (modern) auto repair on flood repair BMW and Audi electrical issues in the late ‘90s. Unfortunately, the industry lends itself to having more parts changers than troubleshooters.

 

[Ellisstrong]

Another update with my truck..I think I figured it all out. I tested something out this morning and I successfully got it to mess up on command. It’s my passenger seat. A little bit of pressure on my passenger seat messes the truck all up. Obviously I have to figure out why the seat is causing me fits yet, but I’m very pleased that I’ve at least narrowed it down. Anyone have any clue as to why the seat would be causing these issues?

So yours never gave you any issues when riding with no passengers? I need to check that with mine but I believe mine messed up when I was driving by myself at some point too.

 

[ramdude2023]

So yours never gave you any issues when riding with no passengers? I need to check that with mine but I believe mine messed up when I was driving by myself at some point too.

I don’t think it’s ever messed up by myself. Every time I have gotten my truck back from the dealership or taken it to the dealership I’ve never had any issues with it. The only time it would seem to mess up is when I had my wife and kids in the truck with me. So I assumed maybe it was something under the rear seat causing me fits? But clearly I should’ve paid attention to the fact it only messes up when my wife is with me as well. Hopefully you can figure yours out and I’ll post here again when they figure out the actual problem this week or next.

 

[HSKR R/T]

I don’t think it’s ever messed up by myself. Every time I have gotten my truck back from the dealership or taken it to the dealership I’ve never had any issues with it. The only time it would seem to mess up is when I had my wife and kids in the truck with me. So I assumed maybe it was something under the rear seat causing me fits? But clearly I should’ve paid attention to the fact it only messes up when my wife is with me as well. Hopefully you can figure yours out and I’ll post here again when they figure out the actual problem this week or next.

Sounds like a good way to screw with the wife and tell her it's all her fault. And that she has to ride in the back seat from now on

 

[Vulpes]

The auto repair industry has been dealing with stuff like this for a few decades, so good techs are well adept at dealing with chasing grounds. I even cut my teeth in (modern) auto repair on flood repair BMW and Audi electrical issues in the late ‘90s. Unfortunately, the industry lends itself to having more parts changers than troubleshooters.

I'll bet those flooded cars were really challenging to get back on the road. And yes I hear all the time about the "parts cannon" as others have mentioned. I did not have much of an understanding of the CAN before this truck, my previous truck, a Dakota was essentially trouble free for the 17 year I had it. I've been watching several CAN diagnostic Youtube channels, and there is definitely an art to it.

 

[ramdude2023]

I don’t think it’s ever messed up by myself. Every time I have gotten my truck back from the dealership or taken it to the dealership I’ve never had any issues with it. The only time it would seem to mess up is when I had my wife and kids in the truck with me. So I assumed maybe it was something under the rear seat causing me fits? But clearly I should’ve paid attention to the fact it only messes up when my wife is with me as well. Hopefully you can figure yours out and I’ll post here again when they figure out the actual problem this week or next.

It ended up being the passenger seat weight sensor for the airbag. They slapped a new one in and it’s been problem free ever since. Even with my wife riding along! Lol

 

[Ellisstrong]

It ended up being the passenger seat weight sensor for the airbag. They slapped a new one in and it’s been problem free ever since. Even with my wife riding along! Lol

I wish mine was something simple like this.I am still trying to figure out mine but it does it frequent enough that I’m hopeful to get some kind of repeatable process that causes it to do it and narrow down the possibilities of what is causing it.

 

[Tripolet333]

I had all my warning lights go off back in July on two separate occasions. Dealer had it for a month and said it was a CAN bus issue but they couldn’t tell me what was causing it and sent it home with me last Friday. I have a BlueDriver scanner and started keeping it plugged in since then just in case I encounter the gremlin again.

Tonight I got home from work and decided to run a scan to see if anything was there after driving it and I have a new confirmed code: U0001 for the Instrument Panel Cluster. I never considered the cluster as part of the network…could this be my issue? Or is the cluster just reporting that it senses a CAN bus issue?

I plan to reach under the dash later and see if there’s anything loose…

 

[HSKR R/T]

I had all my warning lights go off back in July on two separate occasions. Dealer had it for a month and said it was a CAN bus issue but they couldn’t tell me what was causing it and sent it home with me last Friday. I have a BlueDriver scanner and started keeping it plugged in since then just in case I encounter the gremlin again.

Tonight I got home from work and decided to run a scan to see if anything was there after driving it and I have a new confirmed code: U0001 for the Instrument Panel Cluster. I never considered the cluster as part of the network…could this be my issue? Or is the cluster just reporting that it senses a CAN bus issue?

I plan to reach under the dash later and see if there’s anything loose…

The cluster is most definitely part of the canbus network.

 

[Vulpes]

I had all my warning lights go off back in July on two separate occasions. Dealer had it for a month and said it was a CAN bus issue but they couldn’t tell me what was causing it and sent it home with me last Friday. I have a BlueDriver scanner and started keeping it plugged in since then just in case I encounter the gremlin again.

Tonight I got home from work and decided to run a scan to see if anything was there after driving it and I have a new confirmed code: U0001 for the Instrument Panel Cluster. I never considered the cluster as part of the network…could this be my issue? Or is the cluster just reporting that it senses a CAN bus issue?

I plan to reach under the dash later and see if there’s anything loose…

Instrument clusters can go bad, their connectors can also be compromised and that can make the CAN very very angry. One thing that happens is folks have their windshields tinted, and the installation can allow water into the dash which can short various things and also make the CAN angry.

Does your Bluedriver show the waveforms for the various modules?

Attached is a picture of the plugs for instrument panel.

 

[Tripolet333]

Appreciate all the info! I don’t have tinted windows, in fact, the truck is pretty much in the same shape it was when I bought it in 2019 (I’ve got a ‘75 Plymouth as my tinker toy). I did have the windshield replaced 2-3 years ago for a crack, but I don’t suspect a leak to be the issue.

I tried looking up under the dash but it’s a mess of wiring and the frame appears to be directly behind it. I think you can only pull the cluster out from the front, so I’ll let the dealer mess with it.

@Vulpes - when you say waveforms, do you mean the CAN high/low signals? No, the BlueDriver doesn’t show that. I have been thinking about picking up a scope though if this continues to be a problem.

 

[Vulpes]

Appreciate all the info! I don’t have tinted windows, in fact, the truck is pretty much in the same shape it was when I bought it in 2019 (I’ve got a ‘75 Plymouth as my tinker toy). I did have the windshield replaced 2-3 years ago for a crack, but I don’t suspect a leak to be the issue.

I tried looking up under the dash but it’s a mess of wiring and the frame appears to be directly behind it. I think you can only pull the cluster out from the front, so I’ll let the dealer mess with it.

@Vulpes - when you say waveforms, do you mean the CAN high/low signals? No, the BlueDriver doesn’t show that. I have been thinking about picking up a scope though if this continues to be a problem.

Yes exactly on the waveforms = CAN high/low signal.

Watching techs on youtube troubleshoot these issues with the high low signal has been really eye opening. In fact here is one example, while not a RAM, still a Chrysler product :

I am far from really educated/proficient on this stuff, just some guy frustrated with a fairly new truck (just out of warranty when most of the issues turned up) and no desire to go to a dealership.

What model of Plymouth are you modding?

 

[Tripolet333]

I get it, it’s a frustrating experience. Mindset Mechanic also has some great videos around diagnosing CAN bus issues as well.

It’s a 1975 Plymouth Duster. Stock 318 but I added a 4bbl carb, Eddy performer intake, dual exhaust. It’s nothing fancy, but fun to drive. Don’t get much time to work on it these days with the kiddos running around though.

I called the dealer today, I was told the cluster U0001 code I’m seeing is a “stored” code and they need an “active” code for them to work on it. Should I just be looking for an independent mechanic that can diagnose electrical and CAN issues? The dealer seems to be of no help so far…

 

[Ellisstrong]

I get it, it’s a frustrating experience. Mindset Mechanic also has some great videos around diagnosing CAN bus issues as well.

It’s a 1975 Plymouth Duster. Stock 318 but I added a 4bbl carb, Eddy performer intake, dual exhaust. It’s nothing fancy, but fun to drive. Don’t get much time to work on it these days with the kiddos running around though.

I called the dealer today, I was told the cluster U0001 code I’m seeing is a “stored” code and they need an “active” code for them to work on it. Should I just be looking for an independent mechanic that can diagnose electrical and CAN issues? The dealer seems to be of no help so far…

I’m trying to find an independent mechanic in the atlanta area too. I just made a appointment with the dealer I’ve had the most luck with here in atlanta metro but couldn’t get one until 9/25 and I’m not too positive they will be able to fix it