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Q: Does a new ECM for this year make model need to be flashed in order to drive the vehicle? 2004 Ford Focus

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Considering purchasing a 2004 ford focus with a bad ECM. Id like to replace the ECM but id like to know if I need flash the ECM in order to drive the vehicle. If so, what side effects will I have from driving this car with an unflashed ECM.

My car has 179000 miles.
My car has an automatic transmission.

Yes, a new ECM will have to flashed before you can even start your vehicle. The "flashing" or programming of the ECM will require your VIN number to the supplier, who should be updating the most current software for your specific vehicle. Otherwise, you would have to tow the vehicle and the new ECM to a Ford dealer for this service. Make sure your parts supplier has the capability of doing this before selecting them so your replacement will not leave your stranded.

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