Blinking check engine light

[georgew48]

Coming home yesterday I started getting an intermittent blinking check engine light. It would only blink a couple of times and only when going down hill with my foot off the gas. As soon as I pushed the gas pedal back down it would go off. The engine is running fine and no loss of power. My scan tool identified it as a code p300 which Is random misfire. Like I said no rough running and no fluxiuation in the rpm and no loss of power. MPG average was just over 7 mpg. Called the ford dealer this morning and they are going to look at it. Hopefully nothing serious.

[Iggy]

What year is your Georgetown chassis and how many miles?
It's always good to be aware of possible conditions like this.
My 2012 has over 40,000 miles and never did it.

Now I do add some of the injector cleaner when I plan on driving a few thousand miles. It just may be time for some fuel additive in the tank.


This is what I have used a few times. This bottle is used for 100 gallons of fuel but I have dumped all of it in when I do a full fill up of my 80+gallon tank.

[VinceU]

Originally Posted by georgew48

Coming home yesterday I started getting an intermittent blinking check engine light. It would only blink a couple of times and only when going down hill with my foot off the gas. As soon as I pushed the gas pedal back down it would go off. The engine is running fine and no loss of power. My scan tool identified it as a code p300 which Is random misfire. Like I said no rough running and no fluxiuation in the rpm and no loss of power. MPG average was just over 7 mpg. Called the ford dealer this morning and they are going to look at it. Hopefully nothing serious.

Here's my first guess
Is your Check Engine Light haunting you from the dash like a tiny, orange, burning ember? If it is, there's a fairly good chance that a bad O2 sensor is causing the problem. These sensors go bad all the time. Some experts say that new fuels with higher ethanol content are causing parts of our cars, including the O2 sensors, to go bad prematurely. Whether this is the case or not, if your CEL (Check Engine Light) is on you won't be on the road much longer thanks to most states' inspection programs.

Of course before you go replacing an O2 sensor you'll want to be sure that's the problem. Even the parts are expensive, not to mention the labor if you're paying a shop to do the work for you. A Check Engine Light can mean a lot of things, and even though the oxygen sensor is often the culprit, there are hundreds of other possibilities.

[1A Camper]

On our car we were told a solid on light was service was needed but a blinking light we needed to stop driving. I would be calling some shops to find out for sure to see what they said.

[TURBS]

Random misfire is likely a coil or plug.
Just worked on one yesterday.
Plug would intermittently misfire at 45 - 50 mph no miss before or after


2015 Columbus 320RS
2008 2500HD Duramax
2015 nights camped "34"

[georgew48]

Originally Posted by Iggy

What year is your Georgetown chassis and how many miles?
It's always good to be aware of possible conditions like this.
My 2012 has over 40,000 miles and never did it.

Now I do add some of the injector cleaner when I plan on driving a few thousand miles. It just may be time for some fuel additive in the tank.


This is what I have used a few times. This bottle is used for 100 gallons of fuel but I have dumped all of it in when I do a full fill up of my 80+gallon tank.

Mine is brand new only has 1000 miles on it and it had 310 when I picked it up.

[georgew48]

Got an appointment to take it to the Ford dealer. It is under warranty so they can fix it. Only had 1000 miles on it. We just bought it in December and this was our first trip in it. I have a feeling it is something electrical because the engine runs too smooth and had plenty of power and zero fluxiuation in the rpm's. I would think that if it was misfiring it would be running rough or at least the tach would show an rpm fluxiuation.

[Kevin & Judy]

X2
Lucas fuel conditioner, Have used in for the last 15 or so years in all our cars,trucks, motorhomes, Gas or Diesel, It is an excellent product. Have never had any engine related problems. My old 1995 Jeep with 297,154 miles on it. Original engine and transmission. That has had the lucas oil supplepment in it,

[rvpezzano]

The Ford tech will run your VIN number through their OASIS system with the code and/or symptom. If there are any TSB's or Special Service Messages it will show. There also may be an update for the PCM or TCM. The info will point the tech in the right direction if it shows it.

[mtdh]

Did you have your cruise control on going down hill? I had a diesel mh that did that. But once you stepped on the throttle, or started going up hill, it went off.

[georgew48]

Yes I had the cruise on. And that's exactly what mine is doing.

[beachcamper]

Flashing check engine light indicates a condition which is harming the catalytic converter. Usually overly rich condition from bad 02 sensor or misfiring plug. If engine is running smooth then its bad 02 signal. Dealership will scan for stored codes.

[beachcamper]

Just remembered. Bad vacuum leak can cause overly rich condition because it tricks 02 sensor. But that would cause high idle.

[RVnut]

Under any load a motorhome creates you would feel any kind of misfire very easily.. I would say a batch of bad gas or bad o2 sensor..

[Brewhedd]

From CarMD


In today’s Fault Code Spotlight I will explain one of the most common and severe fault codes in your vehicle – misfire. Misfire is a very serious problem and one you should never ignore. The fault codes that you will see for misfire are:

P0300- Random/Multiple Cylinder Misfire Detected

P03nn – Cylinder nn Misfire Detected where nn is a 2 digit number (01, 02…11, 12) indicating the cylinder in your vehicle 1-12.

P0313 – Misfire detected due to low fuel level

P0314 - Misfire detected single Cylinder not determined

P0315 -Misfire Detected due to crankshaft position sensor

P0316 – Misfire detected during engine startup

The most common method for detecting misfire is called crank pulse fluctuation. At an engine speed of 7,000 rpm, your vehicle’s computer is processing 2,800 crank pulses every second! The onboard computer works with the crank pulse sensor to look for fluctuations in the signal to determine if your engine is misfiring. It then triggers the check engine light if it sees a problem.

There are two types of check engine light warnings that all drivers need to be aware of. The first – and more severe is a Type A misfire, which is represented by a flashing check engine light. This flashing check engine light means you are doing “mechanical damage” (read in a deep ominous voice designed to imply very large repair bills by continued neglect) to your vehicle if you continue to drive under these conditions. If you see a flashing check engine light you should seek immediate professional advice.By mechanical damage we are talking about things like the catalytic converter, the exhaust manifold, pistons, rings, valves – virtually all upwards of four-digit repair bills.

[Still Kickin]

Originally Posted by georgew48

Coming home yesterday I started getting an intermittent blinking check engine light. It would only blink a couple of times and only when going down hill with my foot off the gas. As soon as I pushed the gas pedal back down it would go off. The engine is running fine and no loss of power. My scan tool identified it as a code p300 which Is random misfire. Like I said no rough running and no fluxiuation in the rpm and no loss of power. MPG average was just over 7 mpg. Called the ford dealer this morning and they are going to look at it. Hopefully nothing serious.

When your CEL blinks, meaning in a defined pattern, not clear then return, it means it is reading the next level up of code(s) which in turn tell the CEL to blink, is more severe than a constant ON. Do this first before you head off to the stealer, because you seem to describe constant ON, then self clearing. I'll assume you're out of warranty, if not let them fix it .Clear the code, drive it, and if the CEL returns, re-scan it to pull the code.
Random misfire might indicate one of the coil packs is failing. Whats confusing is usually a coil pack fails outright. The other thing might be a fuel injector issue (i.e. clog, failure starting). When your CEL clears by itself, the intermittent problem occuring has stopped, causing the main ECM to reset the CEL to OFF, after the sequence meets design specs.
This information you learn will help you when dealing with your stealer,is trying empty your wallet.

[doc73]

I was always told a flashing CEL is a bad situation where you should stop driving or risk damage. I believe it was misfiring that made it bad..??? MAYBE?

[B47]

Originally Posted by TURBS

Random misfire is likely a coil or plug.
Just worked on one yesterday.
Plug would intermittently misfire at 45 - 50 mph no miss before or after


2015 Columbus 320RS
2008 2500HD Duramax
2015 nights camped "34"

I tend to agree. I had the same issue,but on a different vehicle. I drove it a few miles and the light went out. Did a code check and got the same result. No problem since. Random is the key word here.

[Still Kickin]

Oops, should have read the string. Let Ford fix it. I would however, talk with the tech directly to get his honest experience on what he sees with units like yours after the fix. That knowledge my friend, will save you bundles when it's on your dime.

[HONDAMAN174]

Flashing CEL is for emissions related issues. For the OP-his light stops flashing which means temporary issue. He already has appt with dealer and sounds like he is well within warranty. What will suck is that unless they can repeat the conditions, they will say no problem found. Driving downhill with cruise on- that's a hard condition to duplicate. Going uphill and high RPM's- much easier.


2014 Evo 2850 "Woodstock"
2011 Toyota Tundra "Clifford"