stupid question about flashing PCM

[puckdodger]

Hey folks,

When switching between the Unleashed towing and performance tunes, should I return the truck to stock then flash the other tune? Or just put the performance tune in and don't worry about it?

Thanks!

Sponsored

 

[Wytchdctr]

Curious as I am about to buy a tuner myself.

 

[Dgc333]

Over the years when I flash from one tune to another from the same tuner I don't go back to stock and that includes Unleashed. But if I was going to go from a SCT canned tune to one from another tuner or tuner to tuner I go back to stock first. Never heard a definitive answer if you need to but I would rather error on the conservative side.

 

[Wytchdctr]

Over the years when I flash from one tune to another from the same tuner I don't go back to stock and that includes Unleashed. But if I was going to go from a SCT canned tune to one from another tuner or tuner to tuner I go back to stock first. Never heard a definitive answer if you need to but I would rather error on the conservative side.

Logical. I might go from one tune to another depending on what is in the tank and what I am doing with the truck. Thank you for the feedback

 

[Joeiconic]

Doesn’t seem like it would matter since it’s just a computer program that you are copying over whatever tune you are currently running. Presumably if the stock tune is saved on your install device you can always go back to that.

 

[Dgc333]

Doesn’t seem like it would matter since it’s just a computer program that you are copying over whatever tune you are currently running. Presumably if the stock tune is saved on your install device you can always go back to that.

The tune does not replace all the code on the ECU, it only updates tables. It is conceivable that one tuner may write to different tables than another such that something from tuner 1 does not get over written by tuner 2 and you have could have a compatibility issue and the engine will not run right.

On the Ecoboost Mustang forum this was a real issue. The latter versions of the Ford Performance ProCal3 would not allow you to revert back to stock (the earlier versions did). Several folks tried to install a Cobb tune on top of the FP tune and the engine would barely run. At least they were able to revert to "stock" with the Cobb tuner which in reality was the FP tune. These folks only recourse if they wanted a Cobb tune (and presumably others too) was to go back to the dealer and have them flash the factory tune back onto the ECU.

I have also heard of folks bricking the ECU when when playing fast and free with the tuning device.

 

[puckdodger]

The tune does not replace all the code on the ECU, it only updates tables. It is conceivable that one tuner may write to different tables than another such that something from tuner 1 does not get over written by tuner 2 and you have could have a compatibility issue and the engine will not run right.

On the Ecoboost Mustang forum this was a real issue. The latter versions of the Ford Performance ProCal3 would not allow you to revert back to stock (the earlier versions did). Several folks tried to install a Cobb tune on top of the FP tune and the engine would barely run. At least they were able to revert to "stock" with the Cobb tuner which in reality was the FP tune. These folks only recourse if they wanted a Cobb tune (and presumably others too) was to go back to the dealer and have them flash the factory tune back onto the ECU.

I have also heard of folks bricking the ECU when when playing fast and free with the tuning device.

That makes me think I'm better to revert to stock, them install the desired tune. Thanks for the input.

 

[Joeiconic]

I would be shocked if any reputable tuner didn’t change every single table that was required for the engine to run a tune as designed, even if that meant simply ensuring tables were stock If that is what the tune calls.

 

[Dgc333]

I would be shocked if any reputable tuner didn’t change every single table that was required for the engine to run a tune as designed, even if that meant simply ensuring tables were stock If that is what the tune calls.

Not sure why you would expect that. These guys are not software engineers, not sure they would ever think about something like that.

In any case the stock back up file for my Ranger is 26.5 GB and the tune files are 6.0GB which would indicate to me that the tune file only contains the tables they revised.

 

[got3fords]

I have also heard of folks bricking the ECU when when playing fast and free with the tuning device.

What kind of circumstances would brick the ECU? What is your definition of playing fast and free?

 

[IdahoRanger]

That makes me think I'm better to revert to stock, them install the desired tune. Thanks for the input.

That is what I've always done but never thought about it.

 

[Dgc333]

What kind of circumstances would brick the ECU? What is your definition of playing fast and free?

Turning the vehicle off or unplugging the tuner in the middle of it flashing a tune can brick the ECU. At least with SCT tuners if it tells you to revert the vehicle to stock before updating and not doing it would be in my book playing fast and free.

 

[Dereku]

Always go back to stock when switching from one tuner to another. Otherwise your stock tuning could disappear. Plus the original tuner would remained vin locked until tge stock tune was put back on the truck.

Sponsored