That is what went on my ride. Is this part of the electrical syste...a chip???

the TPS is a variable resistor just like the knob on your old stereo. (the new digital ones? who knows) Also called a potentiometer or pot for short.<p>As u turn the knob, you vary the resistance of the device. This variable resisance can then in turn vary a measured voltage to the Engine computer. The computer can thus sense how hard u are pressing the accelerator my measuring this change in voltage.<p>The part is an electromechanical part: the resistor is electrical, but is mechanical as welll, as it connects to the accelerator, which is a moving part.<p>physically, a pot is a 3 terminal device. <br>Imagine a bare wire wound around a pencil to form a kind of spring. Ucan connect to both ends of the spring. Now add a wiper that touches the spring, and can move back and forth. The closer the wiper moves the either end of the spring, the less resistance there will be. A real pot has different construction, but the analogy is valid<p>hope this helps.<p><br>1996 a4 2.8 qm

Part of the engine management system on most new cars, include a sensor that tells the ECU how open the Throttle body is. It is basically as stated a variable sensor that provides feedback to the ECU on Throttle position. On some vehicles it is important that it is setup to a specific voltage. On these same cars, it is adjustable. I don't know if the one on the A4 is or not, I haven't started messing with this. Mostly this device tells the ECU when you are at half throttle and above. The ECU uses tables that will be based upon this value......Of course with about 27,000 other inputs as well, it's a pretty complex scheme.<p>Alan