Hi there. I have a 2015 Fit LX with AT. I reversed polarity jumpstarting it and now some of the smart electrical things don't work. Here are some of them:
- Cruise Control state resets when I turn off the ignition. I usually leave it in Main On state (press the Main button on the steering wheel) at all times and just press Set when I actually need CC. Now I have to press the Main button every time before Set.
- Headlight's Auto mode doesn't work (lights go dark).
- Central locking system (the buttons on the drivers side door that lock/unlock all doors) doesn't work unless the ignition is on.
- Remote key doesn't work (the small led is flashing when I press buttons on the keyfob but nothing happens, the car won't lock/unlock)
- Power Windows buttons don't work unless the ignition is on.
- The stereo didn't work but I was able to fix that by replacing a blown fuse.

Everything else seems fine, the car runs, turn signals/lights/stoplights work.

I have a new battery now, checked all fuses (Box A under the hood, Boxes A and B under the dash on the driver's side). Only one was blown (the car stereo).
What else can I check to narrow down the problem?
Can I fix this without special tools?

 

I know this thread is a year old, but I have the same exact problem: I had to have the car jumpstarted, and afterward, nothing except the basic necessities work (except while the engine is on). The clock resets to 1:00 every time I start the car. No interior lights to speak of, no stereo/bluetooth/hands-free phone, etc. No remote entry, nothing that I consider a "feature". Heck, even the diagnostic reader circuit is dead!

I checked most of the fuses in Box A under the hood; all of those I checked were OK. Where is the stereo fuse located? I would like to have that back above all else.

 

I ended up taking it to a dealership. This is what they've put in the service records

I hope that helps.