My check engine light is always on. I plugged in my code reader and I get a reads a code 24. When I look this up it is telling me that my vehicle speed sensor may be bad.

Has anyone had to replace one of these before? All I know is that it mounts behind the instrument panel behind the spedometer so before I dive back in there I was wondering if anyone could give some tips and/or tricks that might make this a little easier, or if I even need to bother.

Also does this sensor effect performance. I have heard that it controls your timing advance as your speed increases. Is this true?

What all is effected when this sensor goes south.

I notice that my engine has a pretty limited torque curve. My engine's torque rolls off drastically between 3500 and 4000 rpm. Or is that just normal with an LG4 305?

 

What year is your car...on my 87 the VSS was bad and I replaced it on the transmission not behind the dash...$40.00 part and no problem putting it in just 1 bolt.

 

Does the Check Engine light, indicating code 24, come on while the car is stationary (and then go off after you've driven a block or two)? If so, the manual says to disregard.

JamesC

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Clear the SES code first and then see if it returns. If you had a scan tool, you could verify whether the VSS is actually being picked up the ecm: If the Vehicle Speed remains at 0, then its toast; if it matches the speedo (assuming your have a cable driven speedo), then it may have been triggered by something else.

If you have an electronic speedo, then your VSS must be working if your speedo is giving you the correct reading.

But clear the SES code first. Other sensor errors can trigger a BUNCH of other SES codes. That is why you really need a scan tool to figure these things out. Those code readers are virtually useless IMO.

 

The VSS is in the tranny my friend....not in the dash!! Unless you have an '83 or '84 then you're right!!! '85 and up, it's in the tranny where the electric speedo connector connects to the tranny!! If you don't have an electric speedo then I dunno....but that's what I know about the VSS with an electric speedo!

[This message has been edited by 86TpiTransAm (edited April 04, 2001).]

 

I have an 85 T/A with a 5 speed manual. The engine light stays on constantly whether I am driving or not. I have cleared the codes a couple of times and the problem reoccurs.

 

does your speedo tell you how fast your going? if so ,..the vss isnt comletely shot but, is on its way out!

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89 firebird formula

356 10.5:1compression
comp cams xe262 cam
performer rpm intake
#1405 edlebrock 600
sportsman 2 heads 64cc 2.02/1.60 valves 200cc intake runner
msd 6al
h.e.i. proform 50,000 volt vac. advance ditributor
700r-4 with 3.08 first gear and 3.23 posi 7 5/8 rear end.
b trans shift kit(will kill shifts...suck dong!!)
shorty heddman hedders with custom 3" pipe y-pipe back(no damn cat!) with 40 series flowmaster!


future mods: 406 roller REALLY REALLY REALLY RADICAL!!!!!