Fuel Delivery and Ignition Question...

[Chuck Tomlinson]

> From: peter paul fenske <pfenske at direct.ca>
> 
> For GM VSS or speed sets up various self tests but these generally
> happen at 50 MPH and are not that critical. For an automatic lockup
> control happens at about 35 MPH or so. Ditto for fan control.
> So altering the top speed will not affect the ecm correctly.
> 
> I do believe some of the nissans have active control systems in there
> suspension and steering but the results are generally subjective.
> 
> Remember though ABS also works from this but is usually enabled
> above 40MPH.

AFAIK, passenger car ABS uses only the wheel speed sensors.  The 
resolution of VSS is not useful for wheel speed control (at least 
on GM vehicles).  

Otherwise I agree with you.  I don't see why the ECM would care 
whether engine speed corresponds with vehicle speed at high speeds.  
Sudden changes in VSS may trigger diagnostic faults, but a high 
limit on VSS should be OK.

--
Chuck Tomlinson