2019 1500 check engine light comes on based on the outside temperature and develops a misfire in cylinder 4.

[Whyjustwhy]

Thanks in advance for reading this and offering any input you have.
I have a 2019 ram 1500 5.7 hemi with 135,000 miles on it. I usually keep my ram trucks until they fall apart which is typically 100s of thousands of miles. At about 105,000 miles in this truck started developing the hemi tick and the check engine light would occasionally come on for a few days and then go off. As the miles racked up on it the check engine light would come on and stay on more frequently and for longer periods of time. I will list the codes that I got at the bottom of this post. This winter I noticed that the check engine light would come on and go off based on the outside temperature. When the outside temperature stayed below 50° the check engine light would go off and stay off in the truck would actually run better and the misfire would go away. Now that the temperatures are warming back up here in the Houston area the check engine light stays on all the time and the misfire cylinder for is back pretty much permanent. I don't really notice any problems at all except at idle and when trying to accelerate at speed . I was scheduled to take it into a shop to have the whole engine worked over but what they told me seem to be a little odd when it comes to the problem going away at lower temperatures outside. I am most certainly not professional mechanic but I've worked on lots of mechanical systems and electrical systems and this really puzzles me. Any thoughts?

I just remembered when I would put injector cleaner in the tank it seems like it would trigger the check engine light many times.

P0300 Random/Multiple Cylinder Misfire Detected
P0304 Cylinder 4 Misfire Detected
B1792- Left Rear Lamp Diagnostic Line: Circuit Short To Ground 11
C0604 Active Air Dam Control Circuit Performance P0304 Cylinder 4 Misfire Detected
Mar 08, 2024 8:04 AM

 

[kapinallinen2]

Thanks in advance for reading this and offering any input you have.
I have a 2019 ram 1500 5.7 hemi with 135,000 miles on it. I usually keep my ram trucks until they fall apart which is typically 100s of thousands of miles. At about 105,000 miles in this truck started developing the hemi tick and the check engine light would occasionally come on for a few days and then go off. As the miles racked up on it the check engine light would come on and stay on more frequently and for longer periods of time. I will list the codes that I got at the bottom of this post. This winter I noticed that the check engine light would come on and go off based on the outside temperature. When the outside temperature stayed below 50° the check engine light would go off and stay off in the truck would actually run better and the misfire would go away. Now that the temperatures are warming back up here in the Houston area the check engine light stays on all the time and the misfire cylinder for is back pretty much permanent. I don't really notice any problems at all except at idle and when trying to accelerate at speed . I was scheduled to take it into a shop to have the whole engine worked over but what they told me seem to be a little odd when it comes to the problem going away at lower temperatures outside. I am most certainly not professional mechanic but I've worked on lots of mechanical systems and electrical systems and this really puzzles me. Any thoughts?

I just remembered when I would put injector cleaner in the tank it seems like it would trigger the check engine light many times.

P0300 Random/Multiple Cylinder Misfire Detected
P0304 Cylinder 4 Misfire Detected
B1792- Left Rear Lamp Diagnostic Line: Circuit Short To Ground 11
C0604 Active Air Dam Control Circuit Performance P0304 Cylinder 4 Misfire Detected
Mar 08, 2024 8:04 AM

I just read on the possible causes for the 0300 and 0304, list is really long.
If you have an actual lifter failure ie. hemi tick, then that most certainly could give the misfire codes. You sure it is not a cracked exhaust manifold/s causing the ticking?
1792, just like it says, short to ground or problem with the lamp assembly or the BCM.

So what did the dealer tell you?

 

[Whyjustwhy]

This is an update to this original post.

I had the heads rebuilt with a new OEM cam , MDS delete kit and a new high flow oil pump. Replaced the alternator and serpentine belt. The engine now runs like a top but there are still some electrical problems.

Before going into these strange symptoms that are at least strange to me I'll say that the TIPM and ECM were replaced a little over a year ago. Also had to have the ECM reprogrammed for the MDS delete.

Seems like all the electrical codes that show up are from signals either going to or going from the body control module.
When I start the truck, most of the time I have to press the start button twice to get it to start and it starts immediately on the second press. About half the time when I lock the truck with the key fob, instead of a normal soft chirp, the horn blows as if I was honking at someone. The day that I got it back from the shop, I was driving it home and the stability control warning light came on the dash. About 30 seconds after that the time showed blank, the speedometer went dead, my fuel gauge went to zero and nothing electronic inside the cab was working including the overhead lights locks and windows. Yesterday when I was driving down a very bumpy road the AC, all the interior electrical, and the entire dash went blank for about a second before coming back on and back to normal.

Yesterday evening I disconnected the battery, connected deposit and neutral wires together while I was working, pulled the body control module and checked all of the connections. Everything seems tight and there doesn't appear to be any corrosion or burn marks. Several of the fuses in the box under the dash look like they have gotten too hot but they are not burned out and maybe it's a normal color. I'll attach pictures of that as well as the trouble codes from my scan tool.

I also took apart the wiring harness directly under the driver side floorboard, two of them that are between the fender and the brake booster and clean them with compressed air, then electrical contact cleaner followed by compressed air and put on some dielectric grease before reconnecting them.
Prior to changing the alternator the battery voltage as seen on the dash would read about 13.6 to 13.8. Now it's pretty steady at 14 to 14.2 but occasionally will drop down to 13.7. When I check the battery with the multimeter Everything seems fine and it was just replaced about two months ago.

I'm sure I'm forgetting something but that's all I can remember about things I've done and checked. I'm wondering has anyone experience these problems and what did you do to correct him or do I just need to disassemble every wiring connector on the truck clean and reconnect them. I am wondering if something about my driving habits or areas that I travel to cause problems because the last three ram trucks that I have had developed crazy electrical problems somewhere between 10,000 and 150,000 miles?

 

[Whyjustwhy]

There's another follow up. These ability control light just came back on and then a couple seconds later the break symbol on the dash came on as well as the low fuel and the fuel gauge went to empty the bottom of the center display says no bus battery voltage says zero and the buttons on the steering wheel are unresponsive to change the screen. Almost everything on the interior of the vehicle is dead power wise but the engine is running perfectly fine. The only things that seem to be working on the interior or the rear two windows, the power folding mirrors, and the usb charging port. I can change the fan speed but I'm pretty sure the compressor is not kicking on because the air is not blowing cold. I pulled over to the side of the road to try several things and now all of a sudden everything came back on after sitting here for a minute or two. The only thing that appears to be odd one power came back is the temperature gauge says 100° and it is actually 86°.

 

[kapinallinen2]

There's another follow up. These ability control light just came back on and then a couple seconds later the break symbol on the dash came on as well as the low fuel and the fuel gauge went to empty the bottom of the center display says no bus battery voltage says zero and the buttons on the steering wheel are unresponsive to change the screen. Almost everything on the interior of the vehicle is dead power wise but the engine is running perfectly fine. The only things that seem to be working on the interior or the rear two windows, the power folding mirrors, and the usb charging port. I can change the fan speed but I'm pretty sure the compressor is not kicking on because the air is not blowing cold. I pulled over to the side of the road to try several things and now all of a sudden everything came back on after sitting here for a minute or two. The only thing that appears to be odd one power came back is the temperature gauge says 100° and it is actually 86°.

Dont` know what to tell you, you got your hands full with that one, tail lights taking down the buss?

 

[Pribilof]

Maybe I missed it... did you ever replace left the taillight?

B1792- Left Rear Lamp Diagnostic Line: Circuit Short To Ground 11

 

[Whyjustwhy]

I actually did not replace the taillight.with all the other issues I completely forgot about that.

On another note. Today a new symptom showed up. All the dash lights lit up again and the vehicle started accelerating on its own. I hit the brakes to slow down and when I took my foot off the brake it started accelerating again without me pressing the gas pedal!

WTF!?

 

[Ramboh]

I actually did not replace the taillight.with all the other issues I completely forgot about that.

On another note. Today a new symptom showed up. All the dash lights lit up again and the vehicle started accelerating on its own. I hit the brakes to slow down and when I took my foot off the brake it started accelerating again without me pressing the gas pedal!

WTF!?

Wow that would not sit well with me. With all these messages and lights popping up i couldn't even tell you where to start. Sounds like a serious electrical gremlin.

 

[Pribilof]

Wow that would not sit well with me. With all these messages and lights popping up i couldn't even tell you where to start. Sounds like a serious electrical gremlin.

I'd start with the tail light. As random as that sounds it's caused tons of random weird issues for many on this board.

 

[theblet]

I'd start with the tail light. As random as that sounds it's caused tons of random weird issues for many on this board.

And check the grounds. The main one is on the drivers side behind the battery

 

[Whyjustwhy]

There's a little update. I disconnected and cleaned and reconnected every ground I could get a hold of on the truck over the weekend. I also found that the rear driver side tail light was my problem. Not the passenger side. The wiring connector was pretty well corroded and there is something going on inside the tail light because it has had water in it at some point. I disconnected this until the new replacement shows up and serval of the codes have disappeared but I'm still getting lots of things leading back to communication with the body control module. The problem with losing throttle response is still present but instead of it reoccurring within 10 minutes of starting the engine now it takes at least an hour to an hour and a half to start acting up. When I turn off the truck for five minutes or so everything seems to go back to normal but the check engine light is still present. I wonder if it would be worthwhile to pull each fuse and see what the incoming voltage is to each of them in comparison to what it should be to locate a potential short?

 

[kapinallinen2]

I also found that the rear driver side tail light was my problem.

B1792...

 

[kapinallinen2]

I wonder if it would be worthwhile to pull each fuse and see what the incoming voltage is to each of them in comparison to what it should be to locate a potential short?

A short should blow the fuse in question, if the short was upstream then the fuse feeding the fuse should blow and be pretty obvious IMO.
I might have missed it but if you do not have a subscription to alldataDIY, get one, helps a lot to have the service and ts data.

 

[Whyjustwhy]

Another update. I replaced both of the rear light assemblies and while those codes are not showing up all of the rest of them are and the symptoms keep getting weirder. I did go by AutoZone today just to have them test the battery since I purchased it about three months ago and they indicated the battery was good but it needs to be charged. the truck has a new alternator that was installed about four or five weeks ago. Any thoughts on why the battery would not be fully charged? Maybe some type of parasitic electrical draw?

I have been in the truck driving for several hours today and lots of electrical gremlins are still popping up. The latest thing is all of the same electrical problems but occasionally the dash will go blank and say no bus and when it does that the throttle doesn't work and I can't turn the truck off. Within 5 to 10 minutes you can hear something click and reset and everything comes back to life. Cylinder four is evidently misfiring again which is what started this whole diagnostic rabbit hole.

 

[Willyq711]

Did you state yours was a HEMI Etorque, or non? I've seen similar electrical issues, especially with the dash going nuts, whereby the battery was new, but either defective or just that the specific battery brand didn't work with the high needs the engine system. I'd try a higher tier or brand battery, perhaps OEM for the truck. These 5th gen RAMS are very susceptible to change in electrical current and potency. If you've already tried that, then keep in mind that the electrical flow and feed comes through the eTorque system (if indeed you have it) and therefore you may either have a bad module or the battery behind the back seat has gone south.

Any other gremlins that have popped up?

 

[Whyjustwhy]

So today I thought, I wonder if this intelligent battery sensor could be the culprit behind a lot of these weird codes. So I replaced it because it's a relatively inexpensive part and takes like 3.5 minutes and all but two codes have gone away. Even the cylinder 4 misfire is gone. However now I have a P0440 code and a P2138 code. So far none of the crazy electrical issues that I was experiencing before but it's only been about 30 minutes since I changed that sensor.

 

[Whyjustwhy]

I spoke too soon. Literally three minutes after I posted the last reply the accelerator pedal response died and the error messages on the dash are back. I should've known better than to jump the gun and post so quickly.

 

[Montana_]

Gremlins.

Sorry man.