The 2008 Honda Fit Sport comes with keyless entry from the factory that does a basic lock, unlock, and panic mode from the key transmitter. I have both transmitter batteries go out on me at the same time, which erroneously let me to believe that my keyless entry was broken on my car. If the doors or trunk is opened while armed, the horn will honk. For the 2008 Honda Fit Sport trim, there is no vibration or sound sensor in the factory keyless entry, and I do not have the optional security module upgrade. I discovered that the keyless entry does not have a separate independent fuse, but is rather part of the dash/radio/doorlock circuits. If your dash lights, radio, and door locks are all otherwise working, but your remote does not lock or unlock, it is likely your remote battery. The keyless entry module is fairly bulletproof, and the keyless code is not stored in volatile memory, meaning it will not lose programming if you unplug the main battery.

Ultimately I discovered that BOTH alarms had bad batteries at the exact same time. What a coincidence. Here is what I documented in the remote battery replacement that you guys might find interesting.

 

On my car keys are the Tile Pro, a 3D print of the 2008 Fit Sport in Milano Red, locking gas cap key, and the car key, on a titanium keyring.

 

My Fit is from 2007 and my keys look identical. However my battery will only last about 10 hours and get drained dry. There must be a short in my remote somewhere but I can't see where it might be happening.

 

i was recently on reddit and someone who worked at a honda dealership said these keys buttons like to stick which keeps it "on" and drains the battery, maybe look at the buttons? see if they are sticking?

 

Nice job of documenting with clear photos. That Titanium key ring should be strong enough to keep your keys together in case that cute 3D print of Milano Red Fit gets caught on something pulling it out of your pocket LOL.

FYI – I bought my used '07 Fit Sport MT (also Milano Red but faded badly now that it's 12 years old) in 2011 from an independent dealer. It only had one key to my disappointment. I asked why and dealer smiled and said "you'd be surprised how many used cars only have one key. The owner is out driving around looking to sell or upgrade his car. He finds a good deal at a dealer and trades or sells the car on the spot and only has the one key used to drive to the dealer. Owner promises to stop by and drop off the 2nd key but never gets around to it. What a stupid shame because once you don't own the car the key is useless.

We needed a 2nd key for the wife so I went online to buy because Honda dealer price was over 4X the online prices. I found out after several tries buying a 2nd key that nobody could program that the transponder key for just the 2007 Fit Sport is UNIQUE to just that one year. It's unlike any other Honda key. Once I found an online supplier who knew what they were doing a local locksmith had no problem programming my key. Got the key for $38 and programming for $50 so I got off pretty cheap. Got my money back for the wrong keys. Car now has 217,000 miles and still only uses one quart of Mobil 1 5W-20 every 6,000 miles and still gets 34-42mpg depending on speed from 80 to 60mph.

 

Nice job of documenting with clear photos. That Titanium key ring should be strong enough to keep your keys together in case that cute 3D print of Milano Red Fit gets caught on something pulling it out of your pocket LOL.

FYI – I bought my used '07 Fit Sport MT (also Milano Red but faded badly now that it's 12 years old) in 2011 from an independent dealer. It only had one key to my disappointment. I asked why and dealer smiled and said "you'd be surprised how many used cars only have one key. The owner is out driving around looking to sell or upgrade his car. He finds a good deal at a dealer and trades or sells the car on the spot and only has the one key used to drive to the dealer. Owner promises to stop by and drop off the 2nd key but never gets around to it. What a stupid shame because once you don't own the car the key is useless.

We needed a 2nd key for the wife so I went online to buy because Honda dealer price was over 4X the online prices. I found out after several tries buying a 2nd key that nobody could program that the transponder key for just the 2007 Fit Sport is UNIQUE to just that one year. It's unlike any other Honda key. Once I found an online supplier who knew what they were doing a local locksmith had no problem programming my key. Got the key for $38 and programming for $50 so I got off pretty cheap. Got my money back for the wrong keys. Car now has 217,000 miles and still only uses one quart of Mobil 1 5W-20 every 6,000 miles and still gets 34-42mpg depending on speed from 80 to 60mph.