Car problem

SouthCaliDiva · 10-31-2005, 09:58 PM

First let me say I don't know shit about cars, so you'll have to excuse me if I ask something really stupid. :o

Okay, when I went out for lunch my speedometer and tachometer were not working. It was working fine on my way in to work this morning. Drove for about 15 min and the speedo stayed on zero, the tach was at about 10 (as if the car was idling). After 15 min or so, it started moving again, but kind of jerky. And I'm sure the speed wasn't accurate. Got back in the car after my errand and it now appears to be working again.

So here's the question:
-Do speedos/tachs typically fail by themselves or do they usually take something else with it?
-Or, is a failing speedo/tach a symptom of something else going south?

Curiosity questions for extra credit:
-Is the transmission still able to discern how fast the car is moving so it knows when to shift?
-Does the thingy {highly technical term

} that tells the airbags to deploy get its information from the speedo or some other way? IOW, if I wreck when the speedo/tach thinks I'm sitting still will the airbags work, or will I be toast?

Thanks.

**powerman2000** · 10-31-2005, 10:30 PM

Quote:

Originally Posted by SouthCaliDiva

So here's the question:
-Do speedos/tachs typically fail by themselves or do they usually take something else with it?
-Or, is a failing speedo/tach a symptom of something else going south?

They usually fail by themselves. I do find it very interesting that both gauges are malfunctioning at the same time.

Quote:

Originally Posted by SouthCaliDiva

Curiosity questions for extra credit:
-Is the transmission still able to discern how fast the car is moving so it knows when to shift?

Yes, it still knows.

Quote:

Originally Posted by SouthCaliDiva

-Does the thingy {highly technical term

} that tells the airbags to deploy get its information from the speedo or some other way? IOW, if I wreck when the speedo/tach thinks I'm sitting still will the airbags work, or will I be toast?

Not sure on that one, but I would say that it is probably the level of the impact that activates the airbag and not what the speedometer says at the time of impact.

nickhead76 · 10-31-2005, 10:38 PM

speed means nothin about your airbags socal. if you get hit when your parked your airbags would blow also. as long as the impact is hard enough to hit your sensors in the bumper they'll go. trust me.

i sell cars for a living(hate it), and ive been hit twice with airbags. saved my life both times actually.

**EME** · 10-31-2005, 10:41 PM

The airbag deployment has nothing to do with the speedometer, so you're OK there.

From "HowStuffWorks.com"

"The sensor is the device that tells the bag to inflate. Inflation happens when there is a collision force equal to running into a brick wall at 10 to 15 miles per hour (16 to 24 km per hour). A mechanical switch is flipped when there is a mass shift that closes an electrical contact, telling the sensors that a crash has occurred. The sensors receive information from an accelerometer built into a microchip."

Full story:

http://auto.howstuffworks.com/airbag1.htm

- EME

GameDayDog · 10-31-2005, 10:44 PM

Yeah, there's a sensor on the front of the car that determines the force of frontal impact.. that determines if the airbag will deploy..

The good news is.. even if you get drunk & hit somethyng at 10030 mph.. the speedometer will say you were doing 10 mph... Hard to get a ticket for that.

I've actually installed a speedometer & tach before.. there's a lil square pin that goes into the transmission then ya screw it into place ... Ya know.. square shape block goes into square shaped hole.. and the speed of the pin determines the result shown on the speedometer... could be somethyng as simple as the pin being worn smooth... sorta lyke a screw that's been stripped...

I woudn't even worry about it, until I had to go thru inspection..

Peace..~G

SouthCaliDiva · 10-31-2005, 10:46 PM

Thanks guys. You really are the best. :bigthumbu

I'm not going to be able to get into the dealer until Saturday, so I didn't want to take any unnecessary risks.

Damn, only 12,500 miles.

Kia :weaps:

10-31-2005, 09:58 PM	#1
SouthCaliDiva IronMass Donator Join Date: May 2005 Location: H-Town bound!!!!!!!! Posts: 515 Recipes: 0 Rep Power: 9	Car problem First let me say I don't know shit about cars, so you'll have to excuse me if I ask something really stupid. :o Okay, when I went out for lunch my speedometer and tachometer were not working. It was working fine on my way in to work this morning. Drove for about 15 min and the speedo stayed on zero, the tach was at about 10 (as if the car was idling). After 15 min or so, it started moving again, but kind of jerky. And I'm sure the speed wasn't accurate. Got back in the car after my errand and it now appears to be working again. So here's the question: -Do speedos/tachs typically fail by themselves or do they usually take something else with it? -Or, is a failing speedo/tach a symptom of something else going south? Curiosity questions for extra credit: -Is the transmission still able to discern how fast the car is moving so it knows when to shift? -Does the thingy {highly technical term } that tells the airbags to deploy get its information from the speedo or some other way? IOW, if I wreck when the speedo/tach thinks I'm sitting still will the airbags work, or will I be toast? Thanks. __________________ It is by will alone I set my mind in motion. It is by the juice of sapho that thoughts acquire speed, the lips acquire stains. The stains become a warning. It is by will alone I set my mind in motion.

10-31-2005, 10:38 PM	#3
nickhead76 PLATINUM MEMBER Join Date: May 2005 Posts: 283 Recipes: 0 Rep Power: 8	speed means nothin about your airbags socal. if you get hit when your parked your airbags would blow also. as long as the impact is hard enough to hit your sensors in the bumper they'll go. trust me. i sell cars for a living(hate it), and ive been hit twice with airbags. saved my life both times actually. __________________ PLATINUM MEMBER

10-31-2005, 10:41 PM	#4
EME Super Moderator Join Date: Mar 2005 Posts: 3,265 Recipes: 0 Rep Power: 51	The airbag deployment has nothing to do with the speedometer, so you're OK there. From "HowStuffWorks.com" "The sensor is the device that tells the bag to inflate. Inflation happens when there is a collision force equal to running into a brick wall at 10 to 15 miles per hour (16 to 24 km per hour). A mechanical switch is flipped when there is a mass shift that closes an electrical contact, telling the sensors that a crash has occurred. The sensors receive information from an accelerometer built into a microchip." Full story: http://auto.howstuffworks.com/airbag1.htm - EME __________________ PhysiqueFXonline - Online Nutrition and Training with Michael and Kendra Elias: www.MichaelandKendra.com Team Molecular Nutrition Creative Director FAME Media Group / World Natural Sports Organization Editor-In-Chief FAME Magazine www.FAMEWorldTour.com

10-31-2005, 10:44 PM	#5
GameDayDog The Dawg Is Back!! Join Date: May 2005 Location: Doin Compound Movements 4 Scooby Snacks! Posts: 1,914 Recipes: 0 Rep Power: 32	Yeah, there's a sensor on the front of the car that determines the force of frontal impact.. that determines if the airbag will deploy.. The good news is.. even if you get drunk & hit somethyng at 10030 mph.. the speedometer will say you were doing 10 mph... Hard to get a ticket for that. I've actually installed a speedometer & tach before.. there's a lil square pin that goes into the transmission then ya screw it into place ... Ya know.. square shape block goes into square shaped hole.. and the speed of the pin determines the result shown on the speedometer... could be somethyng as simple as the pin being worn smooth... sorta lyke a screw that's been stripped... I woudn't even worry about it, until I had to go thru inspection.. Peace..~G __________________ I am Thee Alpha.. RaSP is Thee oMEGA.. Between the 2 of us - We have everythyng covered... I want to be bigger than all the humans!! "I'm sure I should be doing cardio too....but I don't run from anything...so why practice?" - 1stInDoor Goal - 200#'s 5/27/07 - 4/27/07 - 175# 3/27/07 - 167#

10-31-2005, 10:46 PM	#6
SouthCaliDiva IronMass Donator Join Date: May 2005 Location: H-Town bound!!!!!!!! Posts: 515 Recipes: 0 Rep Power: 9	Thanks guys. You really are the best. :bigthumbu I'm not going to be able to get into the dealer until Saturday, so I didn't want to take any unnecessary risks. Damn, only 12,500 miles. Kia :weaps: __________________ It is by will alone I set my mind in motion. It is by the juice of sapho that thoughts acquire speed, the lips acquire stains. The stains become a warning. It is by will alone I set my mind in motion.

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