Flashing Check Engine Light

Started truck this morning. Solid Check Engine and Traction Control Off lights came on. Drove about a mile, Traction Control light stayed on, but Check Engine started flashing. I drove about two blocks to get home, then had it towed to the dealership. This is a 2018 TRD Sport with about 43,000 miles on it. Hoping to hear from the service department tomorrow, but wondering what the problem could be. Anyone with a similar experience or any service tech with some insight would be appreciated. Thanks.

 

My 2011 just started doing the same but the check engine and tac off just stay on don’t flash. I heard it could be a few things something as simple as a gas cap even. I will take mine to a autozone store and have them hook up and get the error code and go from there. You can also disconnect the battery for a few minutes and see if it resets I hear.

 

Flashing check engine light is a catalyst damaging misfire, meaning fuel is still being sent into the cylinder and cannot be controlled or burnt by the ecu.

I'd suspect an injector or a really fucked coil. Valves are a possibility but unlikely.

 

At first, it felt like I had a flat, but it was the engine running rough. More noticeable when sitting at a stoplight. Definitely felt like it was missing.

 

Are you still under warranty?
If so, take it in and don’t worry about it.
They’ll get it fixed for you.

 

Does the fuel pump recall apply to your truck?

 

Agreed that it usually has to do with catalytic efficiency. However, it doesn't make any sense that the catalytic converter would have an issue with so few miles. Even our work vehicles don't have that and they idle A LOT.

 

It'd be cool if there was some diagnostic tool or system that would tell you why a malfunction indicator light illuminates.

 

When my engine had a burnt valve requiring new heads at 32000 miles the engine light was steady and not flashing. It was only idling a little rough. So I'm hoping you have a less severe problem.

 

Not efficiency, damaging. Raw fuel and high temps damage the catalytic converter.

 

Hope it's not to serious .

 

+1 for bad coil pack or injector

 

Buy a BLUEDRIVER...plugs into your OBDII port under the driver side dash...gives you a wealth of info about the state of your vehicle along with error codes.

 

I bet it's just like a Ford. The pcm failsafe strategy is trying to protect the Cats. It will turn off the injector and flash the check engine light to warn the owner. Ford calls it FMEM (failure mode effects management). Emsision laws require all Manufacturers to closely monitor engine operation via OBDII. For those who want to learn more here is Ford's info on this topic (this only a small bit from a 2018 OBDII manual !) :

"The number of misfires is counted over a continuous 200 revolution and 1000 revolution period. (The revolution
counters are not reset if the misfire monitor is temporarily disabled such as for negative torque mode, etc.) At the
end of the evaluation period, the total misfire rate and the misfire rate for each individual cylinder is computed. The
misfire rate is evaluated every 200 revolution period (Type A) and compared to a threshold value obtained from an
engine speed/load table. This misfire threshold is designed to prevent damage to the catalyst due to sustained
excessive temperature (1832°F for Pd-only high tech washcoat). If the misfire threshold is exceeded and the
catalyst temperature model calculates a catalyst mid-bed temperature that exceeds the catalyst damage threshold,
the MIL blinks at a 1 Hz rate while the misfire is present. If the misfire occurs again on a subsequent driving cycle,
the MIL is illuminated.
At high engine speed and load operating conditions the Monitor continuously evaluates the misfire rate during each
200 revolution period. If a sufficient number of misfire events have been accumulated within a 200 revolution block
such that the misfire threshold is already exceeded before the end of the block has been reached, the Monitor will
declare a fault immediately rather than wait for the end of the block. This improves the capability of the Monitor to
prevent damage to the catalyst.
If a single cylinder (i.e. > 90% of misfires attributed to one cylinder) is determined to be consistently misfiring in
excess of the catalyst damage criteria, the Monitor will initiate failure mode effects management (FMEM) to prevent
catalyst damage. The fuel injector to that cylinder will be shut off for a minimum of 30 seconds. Up to two cylinders
may be disabled at the same time on 6 and 8 cylinder engines and one cylinder is disabled on 4 cylinder engines.
Fuel control will go open loop and target lambda slightly lean (~1.05). The software may also use the throttle to limit
airflow (limit boost) on GTDI engines for additional exhaust component protection. After 30 seconds, the injector is
re-enabled and the system returns to normal operation. On some vehicles, the software may continue FMEM
beyond 30 seconds if the engine is operating at high speed or load at the end of the 30 second period. The
software will wait for a low airflow condition (~1 to 5 second tip-out) to exit from FMEM. This protects the catalyst
should the misfire fault still be present when the fuel injector is turned back on. If misfire on that cylinder is again
detected after 200 revs (about 5 to 10 seconds), the fuel injector will be shut off again and the process will repeat
until the misfire is no longer present. Note that ignition coil primary circuit failures (see CCM section) will trigger the
same type of fuel injector disablement. If a particular cylinder cannot be determined, fuel control will still go open
loop and target lambda slightly lean (~1.05) to limit catalyst temperatures."

 

I vote with Exfordman.

Excellent explanation, sir.

 

I vote valve / valve seat.

 

This, or a bad spark plug with broken electrode, carbon tracking, etc. Could also be mice chewing wires (more common this year with commuter vehicles parked at home for longer periods). @TacoWisco since you are still under the powertrain warranty, take it to the dealer. Though beware you'd be paying out of pocket for chewed wire repairs, possibly to the tune of $1000 for a replacement harness and couple hours labor to diagnose and access.

 

Just had mine checked at autozone and looks like I need new plugs.

 

This is why the Autozone printouts are dangerous. All the ECM can sense is the engine slowing down (using the cam and crank position sensors, all happening at the millisecond timescale) during the specific cylinder's power stroke. If it happens often enough, it trips the misfire code for that cylinder. Misfire can be caused by a lack of fuel, spark, or compression.

 

This truck has 150k miles on a 2.7 liter motor. It is a quiet motor no rattles or noisy lifters etc. so I wouldn’t think compression would be an issue. I will replace the plugs and maybe clean the Mass Air Flow sensor then a new gas cap if it still shows a problem. Go from there