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Unable to unmarry Cobb Accessport to use HPtuners Interface??

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Currently the tune on my ECU is a Cobb stage 3 OTS tune. I am having issues, when trying to switch back to my factory (Ford) base tune, to unmarry my Cobb Accessport from my ECU.

The Cobb Accessport goes into a fault mode and then all I can do is return to a file tune already loaded on my Cobb Accessport.

To date, I have not registered my HPtuners Interface to this ECU, nor attempted to write a tune to this ECU.

I have used my HPtuners Interface, to read settings and data log my ECU.

I have registered my HPtuners Interface to my diesel truck, read factory base tune and loaded modified tune to the truck's ECU, without any issues.

My question, did I do something to cause the problem??



Using HP Tuners hardware and software on a vehicle while the COBB Accessport is the likely cause. In the future, I don't suggest mixing tuning devices on the same ECU. They aren't designed to work with each other. On that note, once the AP is uninstalled and you use HP Tuners, attempting to put the Accessport back on the ECU will likely cause loss of the HPT license.

Contact COBB support and let them know what's occurred, that your goal is to uninstall the AP. I don't know if a repair is possible at this point, but they'll certainly try to help you out.

Thanks for the reply! I have some friends who have been helping me with trying to resolve this issue. Is it ok to share your response with them?

You're welcome. I see you've called COBB support for help using the Accessport functions in the past and I suggest another call to COBB so they can walk you through the Uninstall process if it hasn't completed successfully when you've tried it.

Be sure to have a battery charger hooked up as the instructions indicate before calling, so you're all ready to go. Just make sure the charger isn't over or under charging. The Accessport is perfectly happy over a broad range of voltages, but the stock PCM has specific needs during the install and uninstall process. I usually use 2 amp or 5 amp depending on the car and battery state of charge.

I'm hopeful that as long as you never initiated a flash with HPT, that this will just be a matter of executing the Uninstall in just the right way. Fingers crossed for you!

Thanks again! The Techs at Cobb have been helpful. I plan on contacting them when I get back to my shop.

I've also considered picking up a second hand ECU. Loading my OEM tune and keeping it as a backup. Don't know how difficult or possible that might be, just a thought!?

Modern ECUs are "married" to the immobilizer and generally will not run if you attempt that. The dealership can reprogram the vehicle for another PCM, but only one will work per reprogram and you likely don't want to pay the dealership, and got there and wait, over and over.

If you were keeping the COBB Accessport you could load the stage0 tune quickly any time, which is the stock tune, and makes the vehicle operate as stock, but is still loggable by the Accessport. However, I thought you wanted to to uninstall the Accessport so you can use HP Tuners to tune the car yourself, in which case you would need to uninstall the Accessport and not use it. Perhaps I'm not clear on what you're trying to do?

I was hoping to save the Cobb Accessport and OTS tunes, in case,in the future, I decide to return the car to street use and run pump gas.

Currently the car is used "off-road" only and burns E85, using a custom tune, also using my Cobb Accessport.

I have both a 93 octane pump gas tune and E85 tune on.hpt format and ready for testing at the NMRA Spring Break Shootout in February.

I'm concerned that even if I am able to unmarry the Cobb Accessport, from my ECU, I will not be able to return to the Cobb system in the future, after writing new tunes to my ECU, using my HPtuners Interface.

Thanks again for the reply!!

Got it! Makes sense.

I realize that there is more to it than just switching boxes. The replacement ECU will need to be cloned and the key will need to be programmed, plus whatever else!?

I may just have to re-think testing and/or competing, till I can remove the Cobb system completely and restore the original factory software.


Uninstall is only a matter of pushing a few buttons on the Accessport and waiting a few minutes, turning the key on and off a few times as long as using another platform on top of it hasn't caused an issue, so I wouldn't over think it. It's not a lengthy or involved process.

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