Very happy it worked but that surprises me that it worked on jack stands. The way it works is the Engine Computer wants to see high manifold vacuum for at least seven seconds. You'll get high vacuum after snapping and releasing the throttle but not for seven seconds. The computer knows from the speed sensors that the car is moving, but the only way the vacuum can be high for that long is if the car is coasting. When the voltage from the throttle position sensor remains steady during coasting, it knows your foot is off the gas pedal. At that point it memorizes the reading from the TPS. Any time after that when it sees that same voltage, it knows it has to be in control of idle speed.
Be thankful this wasn't a Volkswagen. Disconnecting the battery on them requires a tow to the dealership to have numerous computers unlocked before it will come out of park or increase engine speed, if the engine even starts.
Tuesday, July 12th, 2011 AT 12:07 AM