i've been playin with my vss and can not figure outy why it will not send a signal on either pcm i've tried.

this leaves me unable to use a 2 step, and regardless, none of you know my car, how it runs or anything. a 2 step is good for track use, greatly improves consistancy.

my question is can i change the signal for 2 step control in crome? if not, what reference voltage does the pcm need to be able to switch on a "vss" signal, and not hit fuel cutoff for a speed limiter?

 

Have you tried a new VSS? Maybe the problem isn't with the ECU. You should try and replace the vehicle speed sensor or repair the short in the wiring and see if you can get a proper signal going to the ECU. Does your speedometer work?

 

i just replaced the vss a week ago, and when i did, i checked the wiring as well. i had a good 12v on the ground side(meter plugged into ground on vss, straight to battery +) and also had good 12v input at teh sensor(meter to 12v hot on plug, to battery ground) and i check continuity between the ecu side of the plug and the vss plug, but i'm not sure how to check for it grounding out, since the sensor only sends a signal when in motion.

 

There is a way to test the VSS without having the engine running.

With the ignition on, Pos II (engine not running). Jack up the front end and secure the rear tires with blocks and the chassis with jack stands... safety is key. Once you have the car secured with the front wheels off the ground. You want to block the right front tire and slowly rotate the left tire. At this time you should be back probing ECU pins B10 (+) and A26 (-).

If you see the voltage pulse from 0v to approx. 5volts you should replace your ECU.

If you do not see pulses between 0-5v.
Disconnect the B connector only from the ECU. Turn the ignition on and do the same test.

Do you see 0-5v pulses?

Yes - replace the ECU

No - repair the short in the ORN wire between the VSS and the ECU.

 

alright, cool. good advice. will do sometime this week