The check engine light indicates that you need to service a vehicle soon. If your Ford F250 has a flashing check engine light means that there is a catalyst damaging misfire (it can damage the catalytic converter and O2 sensors).
If your truck has a flashing check engine light, it means you need to service the engine now. So don’t drive your truck.
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Blinking Check Engine Light Diagnosis: Ford F250
There will always be trouble codes associated with the Ford F250’s check engine light flashing. The first thing you want to do is look them up with an OBD II scanner.
Check Engine Light Flashing Causes
A misfire is the number one reason your F250’s check engine light will flash.
Your truck’s ignition system consists of spark plugs, plug wires, and ignition coil packs (older vehicles have a distributor that has the same function as coil packs). These parts work in concert to ignite the fuel in the combustion chamber at just the right time.
Random Multiple Misfire
P0300 indicates that your F250’s engine is misfiring, but it can’t detect which cylinder it’s coming from. This code is often thrown when there is a fuel issue, a timing issue, and not just bad ignition components (most likely).
Cylinder Specific Misfire
If the only code your truck has is for a cylinder-specific misfire. Start with pulling the plug and taking a look at it.
These trouble codes correspond with a specific cylinder misfiring (cylinder number corresponds with its place in the firing order). For example, P0301 indicates the Ford F250 is misfiring in cylinder 1.
Although it’s a bad sign when the service engine soon light flashes, when one of these codes comes up with it (and nothing else), it’s almost always one spark plug or ignition coil. A leaking fuel injector can also cause a cylinder-specific misfire code.
There are other misfire-related codes as well, but those are the most common ones.
Fuel System Issues
Keeping in mind that any engine needs air, fuel, and spark for ignition, your Ford F250’s fuel system can often cause the engine to misfire. It can run too lean or rich. Alternatively, there could be too much.
- Fuel Mixture: If the engine is running rich or lean, the engine will misfire and throw the fuel mixture-related codes, such as P0171, P0172, etc…
- Injector Issues: A leaking fuel injector(s) can leak fuel into the combustion chamber at the wrong time, causing a catalyst-damaging misfire. When this happens, there will likely be a cylinder-specific misfire code.
- Fuel Pressure– Too much fuel pressure can cause the injectors to leak. You’ll likely get a code that indicates the vehicle is running too rich and P0300.
While a majority of the time, the flashing check engine light is going to be caused by a misfire related to your F250’s ignition system or fuel system (as stated above), other issues can cause it.
- Your timing chain could have jumped.
- If your F250 has VVT, it may be having issues.
- EGR- The EGR system recycles burnt exhaust gasses back into the combustion chamber.
- Crank/Cam Sensor- When the cam or crank sensors are not being read by the ECM/PCM, it’s impossible to get the ignition timing right. If your F250 does start at all, it’ll run rough.
- It could be a more serious mechanical issue, such as a bent valve, bad lifter, etc…
Can you drive the Ford F250 with a flashing check engine light?
Do not drive your Ford F250 with a flashing check engine light.
When your engine is misfiring, it dumps raw fuel into the exhaust. This raw fuel can detonate, which causes damage to the catalytic converter and the exhaust system itself.
Which is worse, a flashing or non flashing check engine light?
A flashing check engine light means you should not drive your Ford F250 until you’ve fixed the engine.
Check engine light flashing and the truck is shaking
If your F250 is shaking and the check engine light is flashing, it’s likely one or more of your truck’s cylinders is misfiring.
We recommend that you don’t drive, if at all possible, until you diagnose and fix your F250’s flashing check engine light.
Just pretend that it’s letting you know that it will cost you way more money to fix the problem if you keep driving it.