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Discussion Starter · #1 · (Edited)
Howdy all.

My Ecoboost 2015 has 50K miles and started having some electrical issues short after replacing the battery.

Issues: tail light does not go out, engine button does not turn off and when my car reaches 50 miles/h speed start loosing power (requires to keep pumping the accelerator, anyway speed cannot go over 60 miles/h)

I already checked the battery, alternator and fusils and are all good. Brought to an auto electric and they suggested take to Ford dealer for "software calibration". Maybe the ECU was damaged?

Please, is there anybody who faced this issue before or have an idea about it?

Thank You

Updating 10/13: just came from Ford dealer. The representative said has been seeing that issue a lot and suggested to check Youtube for replacing the press brake switch (would cost from 300 to 500 at the dealer), or pay $140 just for the diagnose. I do not think that`s the issue anyway I am going to try it.

ps. I Already tried removing the battery terminal for starting the procedure installation and didn`t work.
 

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Did you follow the replacement procedure for the battery in the owner’s manual? There is a set procedure for running the car following a battery replacement. Did you perform a battery maintenance system (BMS) reset following the replacement. When you say you checked the battery, what did you do to rule out a bum replacement battery?
 

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Have you checked the terminals are free of corrosion and are tight?
 
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Discussion Starter · #4 ·
Did you follow the replacement procedure for the battery in the owner’s manual? There is a set procedure for running the car following a battery replacement. Did you perform a battery maintenance system (BMS) reset following the replacement. When you say you checked the battery, what did you do to rule out a bum replacement battery?
Thanks for answering. The battery was under warranty and was replaced however as you said they did not follow procedure. I tried disconnecting and connecting again but did not work. Maybe damaged the ECU
 

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I will suggest that you remove the battery terminals and wait 5-10 minutes, then touch the leads together to get rid of any residual voltage in the system (I have seen this on other forums, but you should wait for someone else to confirm here). Then reinstall to the battery. The restart procedure is to start the car from cold, and allow to idle up to operating temperature. Once up to temp, allow to idle at least one more minute. Then drive a minimum of 10 miles. This will reset all the fuel trims. The BMS can be reset by pushing the start button (no foot on brake). Within 10 seconds, complete the following: flash the high beams 5 times, then press and release brake peddle 3 times. Battery warning light should flash 3 times if the BMS has reset. Turn off ignition. If BMS reset fails, lock car with fob (not door handle) and allow it to sit for minimum 8 hours.
 

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I will suggest that you remove the battery terminals and wait 5-10 minutes, then touch the leads together to get rid of any residual voltage in the system (I have seen this on other forums, but you should wait for someone else to confirm here). Then reinstall to the battery. The restart procedure is to start the car from cold, and allow to idle up to operating temperature. Once up to temp, allow to idle at least one more minute. Then drive a minimum of 10 miles. This will reset all the fuel trims. The BMS can be reset by pushing the start button (no foot on brake). Within 10 seconds, complete the following: flash the high beams 5 times, then press and release brake peddle 3 times. Battery warning light should flash 3 times if the BMS has reset. Turn off ignition. If BMS reset fails, lock car with fob (not door handle) and allow it to sit for minimum 8 hours.
This sounds very complicated for just replacing a car battery.
 
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