Car dies for split second and comes back.
 

So im not entirely sure what this is but basically on occasion i will be driving and my radio and my electrical will all go black for literally a fraction of a second and then everything will come back on..... thats it. never worse than that. any idea what this could be?
I checked the battery to make sure nothing is popping off terminals and its nice and tight. the only thing off the top of my head is maybe something is wrong with the grounding? or maybe I'm way off.

Wow really? What about the speedometer? Does it go to zero? Man that must not be good for the ECU.

If everything is going dead, that sure sounds like a flakey connection. When running down the road the car runs off of the alternator not the battery but if the alternator quits then the battery will supply the power for a while until it goes dead. So we are looking at a bad connection that affect both the alternator electrical path and the battery electrical path.

I would definitely start by looking at both ends of the battery cables. I mean not just look but remove and clean the connections with a wire brush. Then I would look at that mess of fuse connections that Honda mounted on the positive battery terminal. Remove and clean all of them. After that I would have to get out a schematic and figure out exactly how a Honda Fit is wired.

Are you sure everything electrical in the car shuts off?

The problem could be either on the ground side or on the positive side.

so the gauges do from what i recall go off and come back to where they should be the only one i can recall actually witnessing doing this is the gas gauge but i would assume. that being said as far as the battery goes ill go out there and clean off the terminals but the battery is new so i wouldn't bet on that being the issue. the only other thing i can think of is there may be something wrong with the negative ground maybe the wire is breaking or something ill scope and get back to you guys.

as resolution to this. I unbolted the main ground and gave it a good cleaning and replaced it. It hasn't happened since although it really didn't seem terribly dirty so I'm not entirely sure if this was the issue or not.

My 07 has done this a few times too. I have been told that it is a warning your ECU is going bad. Just a heads up.

i found the problem....i think. so i had a broken axle and it was flinging grease and some of it got on some electrical clips and once i identified that, replaced the axle and cleaned up the grease the problem went away :)

Our 2008 does something like this too, just started last night. Will post when I determine the cause.

Does it happen when you knee bumps the bottom of the steering column ? Right below the ignition? Mine does that.