i keep getting a vss code. i bought a new one and put it in. i got no code for about 10mins. what could be the problem? and does this affect performance any?

i have and 85 iroc. the vss is on the back of the tach. just to let you guys know. someone told me it might be some kind of buffer in the speedO?

 

Until I swapped engines, the Check Engine light popped on in my 85 IROC shortly after start up and remained on until I had driven a block or so, then went off. The GM shop manual says that if the Check Engine light comes on, code 24 (I think it was 24--anyway the code for VSS) and the wheels are NOT turning to disregard. Cool, huh? Gotta love GM.

JamesC

 

well the code comes up when iam a deccelerating. whether iam one the brake or just let off the gas. once i start moving againg it will go away. its making me

 

It doesn't sound like the way the ecm would set the code for vss falure, more like tps or map..

 

thats what i thought too. but when i hook up the scaner it flashes 24
iam going to go ahead a check the tps, because i know the maf is fine.
thanks for the imput.

 

i have no vss in my car, its probly something to do with it

I think the perameters of the code are, over 1000 rpm for 2-3 second with 5% or less throttle ( decel bassicly) This can cause all kinds of codes to pop up.

For example, when myn would go it would do all maf codes, o2, est.. made me go insane

 

Sounds like not all the software in the ECM's are very intelligently written..
There's usually a buffer between the optical pickup in the speedo and the ECM.
I guess your scanner doesn't provide readouts of the different sensor values then..?
If I found the right diagram then a dark blue wire from the TPS goes to connector 2 pin C13 on the ECM, and a brown wire from the VSS goes to connector 1 pin A10 on the ECM.