What does it mean when the speedo does a full sweep?

[Mark42]

Sometimes when I start the 98 'bird the speedo does a full sweep to 120 and then back to zero. Not every time it starts, but its done it twice in the two weeks I've had it.

What doe this mean? Anything to worry about?

[J3$$3]

Re: What does it mean when the speedo does a full sweep?

Mine does the same thing, and sometimes when I lock my doors and the alarm light lights up, the headlights pop up, thats happened 2 times in the 6 months ive had the car.

[Mark42]

Re: What does it mean when the speedo does a full sweep?

I was searching the forums and came across a members post where he said it means the computer has re-flashed. But I'm not sure I'm buying that.

Its been 8 years since I had my Camaro, but I seem to recall it would do the same thing every now and again.

[Crazed98Camaro]

Re: What does it mean when the speedo does a full sweep?

My 98 does the same thing every now and then.

No harm done so far.

[3.4orNothing]

Re: What does it mean when the speedo does a full sweep?

ok,,my friends ford used to do that at starts up,,,turned out the battery was bad or was not for that car,,,,but by changing battery that thing was gone.

[Rob Bell]

Re: What does it mean when the speedo does a full sweep?

A bad battery or alternator will cause all kinds of weird things to happen.

[Blizzard242]

Re: What does it mean when the speedo does a full sweep?

From what I remember, (dont quote me, I could be wrong) whenever you use HP tuners to reflash your pcm, your gauges will do a sweep to some extent. It could be in the same ballpark of your battery running low and have the same effect of people resetting their fuel trims by disconnecting the battery for a certain amount of time. I was thinking a battery issue before I read 3.4orNothing's post so maybe he's onto something.

[pace2006]

Re: What does it mean when the speedo does a full sweep?

From what I remember, (dont quote me, I could be wrong) whenever you use HP tuners to reflash your pcm, your gauges will do a sweep to some extent. It could be in the same ballpark of your battery running low and have the same effect of people resetting their fuel trims by disconnecting the battery for a certain amount of time. I was thinking a battery issue before I read 3.4orNothing's post so maybe he's onto something.

Never seen my gauges do a full sweep, whether from uploading a tune or just a regular start. Then again, my car's been an oddball on some stuff.

[Blizzard242]

Re: What does it mean when the speedo does a full sweep?

"(dont quote me, I could be wrong)"

I was serious^^ lol. I'm a little fuzzy when it comes to remembering things I haven't done in awhile.

[pace2006]

Re: What does it mean when the speedo does a full sweep?

Bah. Skimmed through it and missed that part. Lol. Don't worry though, I won't hold ya to it.