2025 Ram Big Horn Misfire code (P0300).

[eldoradoboy]

came herew to chime in as one of the unlucky 2025 owners with misfire code on cylinder 3 on my day-old 2025 3.6 bighorn. my lease was up on my flawless 2022 bighorn that had the 5.7, I literally had zero things go wrong with that truck in the 33,000 miles and 3 years i had it..

got my 25 the day before thanksgiving and it idled a bit rough in the heavy rain that night.. TG morning it had cooled down to a frigid cold so I remote started which failed as it set the misfire code.. I copied the info and cleared it down but it came right back on that friday morning. (it was even colder out). took it in a couple days ago and they found theres already a star case open, so they updated with my info.. the TSB indicates on 3.6 2025s that cold weather is a factor in setting the code and to return the vehicle to the customer no curent fix available. sad since my previous 2 rams were such good trucks.. I almost went for a laramie with the 3.0 but a buddy of mine is on his second 3.0 in his grand wagoneer so i opted for the bighorn with some added electronics and creature comforts i wanted... hope they get a fix because i want to use the remote start for whats already started as a cold winter here in ohio..

 

[spd32177RAM]

Update on mine, manufacturer says no more diagnostics needed at this time. Just replacing fuel injector and spark plug on cylinder 1. They had to order parts from Detroit so hopefully early next week I’ll have it back. Took them almost 3 weeks to determine a bad fuel injector? Not convinced but we’ll see.

 

[spd32177RAM]

update: dealership replaced fuel injectors and spark plugs. They test drove it, worked great. Then then let it idle for 20 minutes and lo and behold same miss fire issue in cylinder one.

Next Wednesday will be one month they have had my truck. Probably gonna get a lemon lawyer at this point but am torn cause I love the truck!

 

[RedFred]

update: dealership replaced fuel injectors and spark plugs. They test drove it, worked great. Then then let it idle for 20 minutes and lo and behold same miss fire issue in cylinder one.

Next Wednesday will be one month they have had my truck. Probably gonna get a lemon lawyer at this point but am torn cause I love the truck!

That sucks

 

[Cbty2050]

came herew to chime in as one of the unlucky 2025 owners with misfire code on cylinder 3 on my day-old 2025 3.6 bighorn. my lease was up on my flawless 2022 bighorn that had the 5.7, I literally had zero things go wrong with that truck in the 33,000 miles and 3 years i had it..

got my 25 the day before thanksgiving and it idled a bit rough in the heavy rain that night.. TG morning it had cooled down to a frigid cold so I remote started which failed as it set the misfire code.. I copied the info and cleared it down but it came right back on that friday morning. (it was even colder out). took it in a couple days ago and they found theres already a star case open, so they updated with my info.. the TSB indicates on 3.6 2025s that cold weather is a factor in setting the code and to return the vehicle to the customer no curent fix available. sad since my previous 2 rams were such good trucks.. I almost went for a laramie with the 3.0 but a buddy of mine is on his second 3.0 in his grand wagoneer so i opted for the bighorn with some added electronics and creature comforts i wanted... hope they get a fix because i want to use the remote start for whats already started as a cold winter here in ohio..

They have a fix PCM update was released/if not it will be soon. I am talking about the 3.6 only not the 3.0.

 

[eldoradoboy]

Mine just went back in today for its second time and the dealer echoed what’s said here there is a brand new software update. They are going to apply it today or Monday .

 

[eldoradoboy]

thought id come here and give an update... after the software updatre my truck went dead as a doornail sitting on the dealer lot overnight... no power no door unlock etc... dealer got the door open manually and it wouldnt start or light up.. not even a dome light.. then all the sudden the alarm went off and the truck came back to life... ..they checked it out no codes or anything... ive had it back for about 9 days now including a couple 12 degree F mornings and zero check engine lights or rough running... also notice it idles smoother esp when cold.. im thinking they got it all fixed up.. remote start works every time now too. Looking forward to enjoying my new truck like i have the last 2 Rams

 

[stop4it]

Hello guys,
I recently bought a 2025 RAM 1500 Big Hirn from Ryan Auto Mall in Buffalo Minnesota. As I am driving it home from dealer the engine light came on. I called dealer and they told me to take it in for diagnostic. They run tests and came to the findings that it have a code P0300. Now, the technician told me he can’t fix it because the engineers at Dodge manufacturing is working on a fix. This code means a misfire of one or multiple cylinders. Also it can lead to increase fuel consumption. This defect was first discovered in August 2024 but Dodge auto maker. I feel as if I was being deceived by the dealership and not told about this defect. Also the customer rep from dodge told me if continue to use drive truck it will stall. And when the engine light is on it will not start with the remote. I live in Minnesota where winter is brutal. I need to remote start my truck before I drive which is good for engine and defrosting during winter. I want to return this truck cause my expectation of buying a new vehicle is that there will be no issues. I am very frustrated about this and have to drive over 100 miles each time going to dealer and back.

I would all start using the Lemon law and purchase something else. They should disclose the issues with the trucks. I have a 2020 ram, lease is up soon and was going to get another ram but , I need to look in to these issues first.

 

[kaladin]

I bought a 25 RHO and am having misfire codes in the first 70 miles. Dealership is saying it is just a software push, but the signs are there that it could be an issue. I haven't had the vehicle over 2500 rpms and less than 55mph so we will see. I'll let people know the issues I encounter. My light has been 4 times, two under acceleration and twice and cruise. The two acceleration you could feel a shutter, the others you couldn't. When I ran codes I had something like 15 different ones, but they were all related to the misfires

 

[spd32177RAM]

Thought I'd update the thread—it helps to get this off my chest.

My truck has been sitting at the dealership for a month and a half, and it's still not fixed.

I filed a lemon law claim three weeks ago, and they told me it could take 30-45 days to hear back from Stellantis.

I also opened a case with Ram Care, but my case manager has been absolutely useless. On top of that, communication is a struggle because I can barely understand him.

The dealership did provide a rental, but it’s a Nissan Rogue I mean at least give me a loaner truck. I know.....first-world problems, right? but I’m paying for a truck I don’t have, and my patience is running out.

From what I’ve read, this could drag on for months before the lemon law process is resolved.

Anway, hope this gets resolved sooner rather than later.

 

[Jako]

Thought I'd update the thread—it helps to get this off my chest.

My truck has been sitting at the dealership for a month and a half, and it's still not fixed.

I filed a lemon law claim three weeks ago, and they told me it could take 30-45 days to hear back from Stellantis.

I also opened a case with Ram Care, but my case manager has been absolutely useless. On top of that, communication is a struggle because I can barely understand him.

The dealership did provide a rental, but it’s a Nissan Rogue I mean at least give me a loaner truck. I know.....first-world problems, right? but I’m paying for a truck I don’t have, and my patience is running out.

From what I’ve read, this could drag on for months before the lemon law process is resolved.

Anway, hope this gets resolved sooner rather than later.

Sorry for your issues.
Ditto for me with Ram Cares - useless and couldn't understand him and did not call back UNTIL repaired.
No loaner for me while it took 4 months to get my motor replaced under the "lifetime warranty".
On a positive note the motor was replaced and only cost $100 plus tax.

Best wishes resolving the issues.

 

[spd32177RAM]

Sorry for your issues.
Ditto for me with Ram Cares - useless and couldn't understand him and did not call back UNTIL repaired.
No loaner for me while it took 4 months to get my motor replaced under the "lifetime warranty".
On a positive note the motor was replaced and only cost $100 plus tax.

Best wishes resolving the issues.

I will not pay a dime for any repairs I can tell you that I personally find it amazing the consumer has to be inconvenienced during this, especially if the lemon law states I am well within my right to get my money back or a new truck right now.