2019 Ram 1500 DT Bighorn Canbus Issues

[jarrettp556]

Just throwing this out here to see if anyone can think or narrow down some electrical issues with the CanBus system.

• Specs
  • 2019 Ram 1500 DT Bighorn
  • Powetrain - 5.7L Gas Only Hemi
  • Drive - 4WD
  • 60,000 miles
  • Bighorn Level 2 inteiror with 8.4C Uconnet with Nav, Trailer Tow Package

Vehicle will get intermittent lights on the dash consisting of: AutoPark Disabled, Electronic Stability Control light, ABS light, Airbag light, Service Trailer brake system, and ParkSense unavablible messages along with the swichtes on the center stack below the HVAC controls being illuminated indicating a fault in the system. Vehicle will run and drive fine sometimes and other times it feels like the transmission starts to hunt for a the correct gear with rpms going up and down around 500pms and an audible and phyiscal downshift? The issues will clear sometimes while driving with dashlights staying on and the Front and Rear Parksense lights(near the center stack HVAC controls) going from illuminated on start up to being not illuminated indicating everything is fine. Shutting the vehicle off and starting it on again clears the dash lights and everything acts normal. Also the turn signal indicators in the dash cluster will not blink normally, they will be a super slow blink and not the usualy click click click. Attachted are a pics while the vehicle is freaking out.

Vehicle has had and Occupant Resitrant Control module replaced, didnt resolve the issue, it has had a new battery replaced within the past year and didnt resolve the issue either. Vehicle did suffer from the dreaded rear slider window crack and leak and also the third brake light leaking. Was told the rear module under the back seat was fine and did not recieve any water damage.

Definitely a CANBUS issue from the research ive done online. I have an electrical backgound with low voltage DC systems and I know when the modules work as designed a small positive and negative voltage is sent in a data burst(square wave) between modules. I think the park assist module is the culperate. I have not checked the wiring from the rear park sensors up to the module yet. I dont think its a connector or wiring issue issue based on the fact of how intermittent the problem is. Vehicle went 3-4 months before this round of lights and warning messages on the LCD center cluster screen and dash lights. Any Ideas or help would be appreicaited as the techs at the dealer cannot seem to replicate the issue and can only see the stored codes from when the module(s) loose communication with each other. Also I originally thought this was a grounding issue but ive been throught and have checked some of the easier to find grounds, as well as the ground located next to the park sense module and it was tight and did not have any corrosion on it. Again the 3 ot 4 month stretch of no issues makes me think continuity isnt the leading contender of why the modules loose communication with each other.

 

[vincentw56]

Just throwing this out here to see if anyone can think or narrow down some electrical issues with the CanBus system.

• Specs
  • 2019 Ram 1500 DT Bighorn
  • Powetrain - 5.7L Gas Only Hemi
  • Drive - 4WD
  • 60,000 miles
  • Bighorn Level 2 inteiror with 8.4C Uconnet with Nav, Trailer Tow Package

Vehicle will get intermittent lights on the dash consisting of: AutoPark Disabled, Electronic Stability Control light, ABS light, Airbag light, Service Trailer brake system, and ParkSense unavablible messages along with the swichtes on the center stack below the HVAC controls being illuminated indicating a fault in the system. Vehicle will run and drive fine sometimes and other times it feels like the transmission starts to hunt for a the correct gear with rpms going up and down around 500pms and an audible and phyiscal downshift? The issues will clear sometimes while driving with dashlights staying on and the Front and Rear Parksense lights(near the center stack HVAC controls) going from illuminated on start up to being not illuminated indicating everything is fine. Shutting the vehicle off and starting it on again clears the dash lights and everything acts normal. Also the turn signal indicators in the dash cluster will not blink normally, they will be a super slow blink and not the usualy click click click. Attachted are a pics while the vehicle is freaking out.

Vehicle has had and Occupant Resitrant Control module replaced, didnt resolve the issue, it has had a new battery replaced within the past year and didnt resolve the issue either. Vehicle did suffer from the dreaded rear slider window crack and leak and also the third brake light leaking. Was told the rear module under the back seat was fine and did not recieve any water damage.

Definitely a CANBUS issue from the research ive done online. I have an electrical backgound with low voltage DC systems and I know when the modules work as designed a small positive and negative voltage is sent in a data burst(square wave) between modules. I think the park assist module is the culperate. I have not checked the wiring from the rear park sensors up to the module yet. I dont think its a connector or wiring issue issue based on the fact of how intermittent the problem is. Vehicle went 3-4 months before this round of lights and warning messages on the LCD center cluster screen and dash lights. Any Ideas or help would be appreicaited as the techs at the dealer cannot seem to replicate the issue and can only see the stored codes from when the module(s) loose communication with each other. Also I originally thought this was a grounding issue but ive been throught and have checked some of the easier to find grounds, as well as the ground located next to the park sense module and it was tight and did not have any corrosion on it. Again the 3 ot 4 month stretch of no issues makes me think continuity isnt the leading contender of why the modules loose communication with each other.

You've got a grounding issue somewhere. For me, this happened when the top of the rear axle was hitting the exhaust and melted the wiring on top of axle. Every so often, it would hit the exhaust and cause a ground issue.

 

[BlueHemi1500]

I have read on one of the forums where I am a member that there have been potential problems with rear taillights having moisture, and once that issue was resolved the other problems were also solved. I can not remember which forum or topic I read this information.
I read a lot about our trucks to try and keep my keyboard mechanic skills up to par. I do not have the tools nor the practical knowledge/skills to do the work, but at least I know how to do the simple troubleshooting, before sending the truck to a mechanic.

BlueHemi1500

 

[bigdodge]

do you have the rear window leak?

 

[jarrettp556]

do you have the rear window leak?

Yes it did have the rear window leak, both around the rear slider frame and the third brake light. Both of those have been fixed. I was told the rear module under the back seat did not recieve any moisture damage from the leaks but I may need to investigate that module again to cross it off the possilble issues. Or maybe check continuity on the pins of that rear RF module.

 

[jarrettp556]

You've got a grounding issue somewhere. For me, this happened when the top of the rear axle was hitting the exhaust and melted the wiring on top of axle. Every so often, it would hit the exhaust and cause a ground issue.

Hmmm ok. Well maybe I need to chase those more hard to reach grounds then. I did a visual inspection of the rear park sensor harness (Since it runs near the drivers side rear wheel) and did not see any visual damage to the harness or any obvious loose connections, I have a printout of all the ground locations on the vehicle. Grounds in the engine bay have been checked and cleaned.