BlueCruise / ACC Fix – Hard Reset

[jsideris]

Hello all. It’s been a while since I posted here. I Thought this could be useful for anyone else running into this bc/acc issue.

After a year of flawless BlueCruise use on weekly long highway commutes (70–150 miles), I suddenly ran into issues:

• BlueCruise would engage for a few seconds, then immediately disengage
• ACC reacted to phantom speed limit signs
• Predictive speed reductions on curves were extremely aggressive

I contacted app support and tried all the usual troubleshooting:

• Soft reset
• Removing/re-adding the vehicle in the app
• Disabling/re-enabling connectivity and location sharing
• Master reset
• Toggling driver-assist settings

None of that fixed it.

What DID fix it:
A full hard reset by disconnecting the battery

Steps:

1. Disconnect the negative battery terminal
2. Leave it disconnected for 30 minutes
3. Reconnect the battery
4. Reset the BMS:
   
   • Flash high beams 5 times
   • Press brake pedal 3 times

After this, BlueCruise immediately worked normally again. ACC behavior returned to normal, no phantom slowdowns, and everything has been solid for weeks.

This seems to clear cached memory across all modules—something soft resets don’t fully do. I’ve seen similar fixes reported on F-150 and Mach-E forums as well.

If you’re having persistent BlueCruise or ACC issues, the 30-minute battery disconnect is definitely worth trying before heading to the dealer.

 

[angore]

Why reset BMS? A mobile tech did the battery disconnect but did not do a BMS.

 

[jsideris]

Not sure. I was eager to get my blue cruise back so I followed the steps exactly