vehicle speed sensor

[knowleqe]

hey everyone, i just wanted to know what the vehicle speed sensor does. my check engine light shows its the speed sensor. but can it make the car run bad or anything? my speedometer and everything else works, just that the idle bobs and i run rich

thanx-Nick

[[s3]]

Here it is straigt from the FSM:

The vehicle speed sensor provides a vehicle speed signal to the ECM. The speed sensor consists of a read switch, which is installed on the transmission unit and transforms vehicle speed into a pulse signal.

[quiksilvia]

its tells the speedo what to say, they can go bad, buy a new one, then clean the mafs, check vac lines, and possibly get a new o2 sensor for the rich and idle stuff

[NISTECH]

The speed sensor in your car is the speedometer head it self. If your speedometer shows you how fast the car is going. it is not the pick-up wheel in the trans. it is the speedometer head. It is not sending a signal to the ECM. Sometimes its a soldier problem and in others its a logic problem. Yank it out of the dash take a look at the solder mounds on the back of it,if any are cracked heat them carefully with a solder iron add a little extra soldier to it and recheck after clearing the codes.

[quiksilvia]

fsm is wrong, or what ?

[NISTECH]

its japanese translation. its never really clear on the older manuals.

[knowleqe]

i just got my speed sensor replaced 2 days ago and just last night it came back on. should i just reset the ecu and see if it comes back on again? or should i take it back to the shop?

[NISTECH]

if the shop diagnosed it and that was their repair. yes you should take it back to them.