Community Forums

manderson2228 · 09-24-2017, 06:38 PM

Have a new 2018 motorhome and I have 5000 miles on it. During that 5000 miles I have had a check engine light pop up 5 or 6 times. Each time I get a p0300 Random cylinder Misfire code. I've brought it to the dealer 3 times now, the first they flashed the computer, but it came back soon there after. Brought it back to the dealer 2 more times and all I get it we can't duplicate it yada yada. It keeps coming back. No other dealers inside an hour plus of me i'm in Atlanta. Anyone have any advice? I've called the ford f53 chassis hotline thing and they called the dealer and got the same song and dance and accepted the answer.. Something is wrong...

Same dealer literally can't tell me how much for an oil change.. Charged me 240$ for preventative maintenance service where they greased the joints and did the oil change.. When I asked how much for just an oil change they said 400$ so its almost half price to do more work............

Someone help!!

ej1144 · 09-24-2017, 07:04 PM

What engine

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ej1144 · 09-24-2017, 07:05 PM

Could be an o2 sensor

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Cover Dog · 09-24-2017, 07:12 PM

My check engine light comes on almost every trip. Hook up the scanner, P300=random misfire. Clear it until the next trip when it will throw it again. Comp. has been re-flashed at dealer several times.

Does not seem to affect engine performance it's just aggravating.

Thor29.3inAZ · 09-24-2017, 07:14 PM

2017 Thor w/Ford F53 chassis, V10 3V engine. I've had 3 engine lights come on. I bought a OBD reader. It said I had pretty much everything going bad. Less than 10K miles. Come to find out through trail and error, my 5 Star flash was causing the engine light coming on. Once I took it back to stock, had no more engine light. I know this isn't going to help if you have not flashed the ECU but a $65 OBD reader was nice to see what was going on. You could take a picture of the codes and find a different dealer to help you out.

twinboat · 09-24-2017, 07:15 PM

This is what to check. Ford should be following it. As new as it is, wire connections could be the problem

P0300 FORD - Random Misfire Detected

Read more:*https://www.autocodes.com/p0300_ford.html

Possible causes
Faulty spark plug (s)
Faulty ignition coil (s)
Clogged or faulty fuel injector (s) Intake air leak
Fuel injectors harness is open or shorted
Fuel Injectors circuit poor electrical connection
Ignition coils harness is open or shorted
Ignition coils circuit poor electrical connection
Insufficient cylinders compression
Incorrect fuel pressure

Read more:*https://www.autocodes.com/p0300_ford.html

Tech notes The P0300 code means that a cylinder(s) is misfiring or is randomly misfiring. Start by checking for intake leaks, intake gaskets are common caused of multi-cylinder misfiring. If no leak are found the next step is to replace the spark plugs. If the problem persists more tests needs to be done to diagnose problem, see "Possible Causes"

Read more:*https://www.autocodes.com/p0300_ford.html

manderson2228 · 09-25-2017, 05:09 AM

Quote:

Originally Posted by Cover Dog

My check engine light comes on almost every trip. Hook up the scanner, P300=random misfire. Clear it until the next trip when it will throw it again. Comp. has been re-flashed at dealer several times.

Does not seem to affect engine performance it's just aggravating.

Same situation I am having.

I assume you have the F53 same as me right?

manderson2228 · 09-25-2017, 05:11 AM

Quote:

Originally Posted by Thor29.3inAZ

2017 Thor w/Ford F53 chassis, V10 3V engine. I've had 3 engine lights come on. I bought a OBD reader. It said I had pretty much everything going bad. Less than 10K miles. Come to find out through trail and error, my 5 Star flash was causing the engine light coming on. Once I took it back to stock, had no more engine light. I know this isn't going to help if you have not flashed the ECU but a $65 OBD reader was nice to see what was going on. You could take a picture of the codes and find a different dealer to help you out.

The dealer see's the code. They know it's in there and still won't do anything to fix the issue because they can't duplicate it.

Cover Dog · 09-25-2017, 05:53 AM

Quote:

Originally Posted by manderson2228

Same situation I am having.

I assume you have the F53 same as me right?

Same as you in the coach in our signature.

spyderRV · 09-25-2017, 11:44 PM

What are your long term fuel trims? Could indicate a left/right bank fuel problem or a general lean situation. Lets say left banks is rich, the computer will pull fuel from that bank. Now suppose that bank's O2 sensor is incorrectly reporting O2 level and the bank is now too lean, could cause misfires.

TeJay · 09-26-2017, 06:16 AM

Your situation is not unlike several others that have posted. They have an issue they report it to the dealer. The technicians (Techs) do what they have been taught and can't find the problem. It's worse when it's an intermittent problem which they can't duplicate.

There are still symptoms and things to check much of it based on what twinboat listed. Unless you find an old school good diagnostic tech they don't and can't think outside the box so they have a solution.

Another issue is the techs are limited on how much time they can devote to the diagnosis. That is controlled by the dealers and manufacturers. So they do what they have done in the past which is almost nothing.

Back in the early 80's Detroit was preaching diagnosis and getting rid of the parts changers who did not diagnose but simply changed part after part until it was fixed. For a time the parts changers took a back seat but now I'm afraid they are back.

Today's kids entering the field are products of the tech age with cell phones and the thinking that a scanner will tell them which part to change. That is absolutely false. Scanners only read codes and the codes only tell part of the story. Thinking is still involved. Since the kids have been handed everything they can't think outside the box so we don't have many decent techs.

A perfect example is this. Read on these forums. This same story has been told at least twice if not more.

Your brand new RV has a vibration at 60 MPH. You take it to any dealer. They balance the tires, drive shaft, etc, etc and it still vibrates. After months and months and several dealers, tire shops and balances etc, etc they throw in the towel and simply say they can't fix it.

Any vibration at road speed is the result of an imbalance of a spinning object. Since the drive line and tires have been balanced they stop thinking and quit. They assume that the hub or lug centering of the rim /tire is correctly working but they could be wrong. LOL!!!

The service writers do understand the need for diagnosis. I remember well back in the 80's as we got deeper and deeper into computer controls and many of the older techs who hadn't had to learn new stuff refused to learn the newer ways and many just quit. Those who stayed either studied every night or they fell behind. The technology was changing all the time even in mid years and not just at the usual model change over time.

Detroit was making massive changes all the time until about the mid 90's when things began to settle down somewhat.

I'll go out on a limb and say that basically the fuel delivery has been tweaked a lot but the basic technology is the same since the mid 90's except for newer and more involved technology like drive by wire, avoidance warnings, tire pressure monitoring technology and of course transmissions that shift 10 times for improved fuel mileage. These types of bells and whistles have made a surge in recent years which reinforces my belief about fuel and emissions changes slowing down and more bells added.

manderson2228 · 09-27-2017, 06:31 AM

Quote:

Originally Posted by spyderRV

What are your long term fuel trims? Could indicate a left/right bank fuel problem or a general lean situation. Lets say left banks is rich, the computer will pull fuel from that bank. Now suppose that bank's O2 sensor is incorrectly reporting O2 level and the bank is now too lean, could cause misfires.

So i have no idea how to do any of that stuff

and it's also why I bought new so i could let a dealer handle all that!! With that said it sounds like a reasonable potential solution. I'll bring it up with Ford.

TeJay · 09-27-2017, 07:29 AM

What spyderRV, was referring to is called Block Learn and Block Integrator. Those are fancy terms used to describe how the vehicles CPU learns the individual driving characteristics of the persons who drive that vehicle. It's also referred to as long and short term fuel delivery characteristics. Also called, "Adaptive learning."

There are some techs who can look at that information which can assist them in diagnosis of driving and performance issues.

Back in the 80's and 90's when all this stuff was changing like the winds there was talk of BL & BI but seldom was there an instructor who really knew much about what it meant. I know because having attended many, many clinics I asked the questions and got few clear answers.

Here's a few ways it does come into play. For years we have heard statements from customers like, "You tuned up my vehicle and now it drives differently. What did you do?"

Many times what effected the driving was a partially obstructed air filter. With a new filter the vehicle had to re-learn the fuel characteristics based on easier air flow. Just altering the flow of air effects fuel deliver, transmission shifting points etc, etc.

Here's another way things are effected. Dad loans Junior the car for a date. When he drives it to church Sunday morning Dad thinks it feels and acts different. What happened??? Junior was out driving Dads car differently probably racing it.

Those stories may sound crazy but those things do happen and yes driving characteristics do effect how engines operate. It's also a part of the transmission shifting characteristics as well. There is a lot of adaptive learning that occurs.

I doubt your ford dealer knows much about these processes. For the most part it's the engineers who make adjustments. The techs can fix specific issues as they come down from the engineers if something becomes a problem. The new Ford 6-speed in 2016 is a perfect example. Some of those new 6-speeds did not work in the TH (Tow Haul) mode. It took almost a year of complaining before Ford decided to look at and fix it but they did.

Years ago to make these types of changes they'd change a chip. In these more modern times the owners take their rigs to a Ford shop and they do the update through the OBDII connection in less than 30 minutes.

What ever issues you are experiencing eventually if it is something that concerns Detroit they may have a fix for it. You can complain or just ask the service manager if there are any fixes for what you are experiencing. Sometimes they need some prodding.

Most often if you have a complaint the first thing a good tech will do is check for a TSB (Technical Service Bulletin) with your specific complaint.

KTM251ss · 09-27-2017, 11:07 AM

Last winter on my drive to Florida from Michigan, at one of the overnight stops in Savanna I noticed the ck engine was lit, everything seemed fine so I finished my drive to Florida. I remembered I had my scanner from my 5 Star Tune and that is the error message I got with it, so I cleared the error code and it's never come back so far. I just figured that it was a one time thing, maybe an oversensitive reading, I also thought I may have not tightened the gas cap enough, but I doubt it.