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CEL, does flashing ECU or uninstalling AP clear codes? (I don't want to clear my CEL code)

AzNightmare

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#1
My car threw a CEL and having issues and I'm planning to bring it into the dealer.

Will reflashing to Stage 0 or uninstalling the AP automatically clear the code?

I'm past the warranty window so I don't really need to hide the fact I tuned my car, but I just want to revert it back to stock so it helps the tech figure out what's going on easier since they'll be more familiar with the stock settings.

But I obviously don't want my codes to clear if I'm going to get them to diagnose it...

Anyone know?

Thanks.
 


D1JL

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#2
There have some cases where the PCM/ECU could NOT be re-flashed because an AP was installed.
 


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AzNightmare

AzNightmare

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There have some cases where the PCM/ECU could NOT be re-flashed because an AP was installed.
Would you suggest I just uninstall the AP before I take it in?

Apparently my CEL light went off on it's own, but I assume the codes are still going to be present if Ford tech scans my car?
The issue on my car still remains regardless.
 


D1JL

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Would you suggest I just uninstall the AP before I take it in?
Yes, that would be my suggestion as Ford may blame the AP/Tune and refuse to work on the car.

Do you know what the code was?
If it is a hard code the lite would still be on.
However it may be a pending code and the lite can go off.
You should be able to read codes with the AP.
 


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AzNightmare

AzNightmare

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Yes, that would be my suggestion as Ford may blame the AP/Tune and refuse to work on the car.

Do you know what the code was?
If it is a hard code the lite would still be on.
However it may be a pending code and the lite can go off.
You should be able to read codes with the AP.


Yes, I've already checked the code with my AP.
P1450 comes up maybe once every 6 months. I cleared it twice because I assumed it had to do with that infamous issue with the idle dropping right after a fuel fill up.
But just last week, I received a P2196. I cleared it just to see if it was a false alarm.
Then a few days later, I received a P0131.

I think both of those last 2 codes seem to have to do with the O2?

My car during my commute also shut itself off with the red engine oil light on. It disappeared once I turned the ignition back on though. I went back home to check my oil levels but they are fine.
I use my car for daily commuting so I had to keep driving it and every commute, it shuts itself off once...

Definitely time to take it in. I've already made an appointment for the closest available date.
 


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I'm not sure how many miles your ST has on it, but it could be the O2 sensor going bad which isn't uncommon with ST's that have over 50k miles.
 


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AzNightmare

AzNightmare

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I'm not sure how many miles your ST has on it, but it could be the O2 sensor going bad which isn't uncommon with ST's that have over 50k miles.
lol, just under 25k, 40 months first owner...

Not to mention, my trunk lift button failed about 2 months ago, so I can't even get that fix with warranty. Only way I can open my trunk is using the key fob now.

Trying to stay calm... [:(!]
 


D1JL

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#8
Not to mention, my trunk lift button failed about 2 months ago, so I can't even get that fix with warranty. Only way I can open my trunk is using the key fob now.

That button is cheap and easy to replace.
 


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AzNightmare

AzNightmare

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That button is cheap and easy to replace.
If that's the issue. i'll be able to test that out over the weekend since I have a replacement one. Although I didn't see any water damage in the original one so not sure if it's the button or something else.

Do you know if that trunk button has it's own fuse? Although I suspect if its a blown fuse, my key fob trunk function wouldn't work either.
 


D1JL

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Do you know if that trunk button has it's own fuse? Although I suspect if its a blown fuse, my key fob trunk function wouldn't work either.

That is correct.
The FOB works, so the BCM and latch work, so that negates any fuses.
It could be a wire problem but it is most likely the button and the easiest to test/replace.
 


MagnetiseST

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#13
Is this considered under powertrain?

I can Uninstall my AP but it's very apparent I have cobb parts. Any advice? Lol
Find a mod friendly dealer. There may be some in your area that will over look things like intakes, intercoolers and exhausts, so long as the factory downpipe & diverter valve are in place.
 


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AzNightmare

AzNightmare

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Find a mod friendly dealer. There may be some in your area that will over look things like intakes, intercoolers and exhausts, so long as the factory downpipe & diverter valve are in place.
Yes I never swapped out my oem DP. Should I bother even saying I tuned it?
 


MagnetiseST

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Yes I never swapped out my oem DP. Should I bother even saying I tuned it?
If they REALLY dig into the ECU they can see how many times it has been re-flashed. What they immediately see is how many key cycles have been done / counted, this value is re-set every time you flash the car, or remove the battery. I just sat in my car and cycled the key (start / stop engine) like 100 times after I uninstalled.

Typically they don't look into those things unless they have a reason to, like you blew the engine/turbo/trans and Ford wants to know what the operating conditions were.

FWIW: I was full bolt ons, stage 3, custom mountune map. My engine let go. I put everything besides my suspension back to stock, and brought it to ford. they replaced the engine and turbo no questions asked.
 


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AzNightmare

AzNightmare

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Thread Starter #16
If they REALLY dig into the ECU they can see how many times it has been re-flashed. What they immediately see is how many key cycles have been done / counted, this value is re-set every time you flash the car, or remove the battery. I just sat in my car and cycled the key (start / stop engine) like 100 times after I uninstalled.
Do you mean as in starting the engine on and off, or just turning on the power on and off.

---




My car didn't act up yesterday at all.
But this morning, the motor died again with the red oil light on. This only happens once each commute (about 30 mins).

I have no idea how the tech will replicate this issue at the shop or if he'll even be able to.
I'm more concerned if they'll just charge me a flat fee to diagnose codes (which I've already done myself with the AP), just to tell me they can't find anything wrong.

I'm highly suspicious this is related to the infamous Evap purge valve issue.
 


MagnetiseST

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Do you mean as in starting the engine on and off, or just turning on the power on and off.

Start and stop the engine. I let it run for a few seconds each time, and I would not do it if the engine is cold. Start it, warm it up, and let it idle for a while then do it. Cold starts are really bad for engines.
 


rallytaff

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#18
That is correct.
The FOB works, so the BCM and latch work, so that negates any fuses.
It could be a wire problem but it is most likely the button and the easiest to test/replace.
My fobs gave up the ghost and it turned out to be the BCM which was replaced under the warranty which I bought. Cost would have been around $1,500 with labour, but with the warranty, 0!
 




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