The pothole on Elm Street fixed my dash flicker better than the shop did

I’ve dealt with that same bizarre issue where somthing that seems completely unrelated to the impact event is the actual problem. My sedan had the random check engine light flashing for about six months, wich kept me up at night because I thought it was something major like a failing catalytic converter or something similar. I kept planning to get a diagnostic done, but the repairs were expensive, and I started wondering if it was just a software glitch. It finally went away after I took a small bump while turning onto a residential street. It wasn't a deep crater, just a really sharp lip in the pavement that rattled the whole chassis. immediatly, the light went out. It was completely unexpected because the stored error code was still accessible through my scanner.

I had my friend look at it a few days later, and they said it was probly just a sensor harness that vibrated loose and then shifted back into place when the car jolted. It’s amazing how much plastic and rubber insulation can house a connection that is just a few millimeters off. It takes a big enough shake to reseat things that are otherwise fine.

I've experienced something similar but with the cabin climate controls. My Heater control unit for my older sedan started cutting out intermittently, expecially when I was going over bumps. It would work fine at a stop but suddenly it would just stop heating up, leaving me freezing. It sounded like a simple relay problem, but nothing seemed obviously loose behind the glove box.

I was driving through a construction zone last month, and a significant chunk of gravel was thrown up. It hit my fender and seemed to knock something loose, which is probably overkill. The next day, the heating started running consistently at the full setting and stayed there without cutting out. I assumed the impact just jarred a wire or a connector into place. It's frustrating because when things work, you assume they will forever. I checked the fuse box and verified the amperage was fine, but the relay looked physically fine on the outside. It's defintely a wierd universe that sometimes random street debris provides a fix for a wiring mystery without needing a full diagnostic report.

I actually don't buy that it was just a sensor harness vibrating loose and then shifting back into place. If it was realy just a simple loose connection, it usally doesn't fix itself permanently; it usually comes back the second the connection breaks. I’ve had similar issues where the fault code clears but it was actually a failing component or a specific module timing out under vibration, not just a simple physical nudge that moved a wire. You might get lucky once, but it’s more often a symptom of something else wearing out.

The skeptic upthread has a point, but there's a middle case here. A corroded body ground can make contact for months, then a hard jolt scrapes the rust off the mating surface and you get a clean connection again. That one acutally stays fixed. I chased a flickering cluster on my wife's Escape for weeks before I found the ground stud behind the kick panel was loose about a quarter turn. Torqued it down and cleaned the contact, and it's been dead steady for three years now. If the flicker ever comes back, that's where I'd look before blaming a module.

First time posting here so forgive me if this is dumb, but my pothole story went the opposite direction. Hit a deep one on my commute a few months back and my radio, which worked perfectly before, just died that day. Never came back. So now I half wonder if the jolt that fixed your dash could just as easily knock something loose that was fine. Also curious if your fuel gauge stays put after a few weeks, mine used to wander and nobody ever figured out why.

Update: still steady two weeks later, so maybe the guy who mentioned the corroded ground getting scraped clean is onto something, since it actually stayed fixed. The fuel gauge though has started acting up again, drifting low on hills. Would that point to the sender unit instead of a wiring issue? Not eager to drop the tank if the jolt really did reset the electrical stuff.