BMW Repair: Throttle Position Sensor, throttle position sensor, resistance change
QuestionI see from your profile that your expertise is in BMW's newer than mine, but I was hoping you could point me to the right place. I have a 1994 325i. Right at the moment I am trying to find test procedures to test the throttle position sensor with an ohm meter or multi-tester. I have been searching the internet for hours but can't find specifics. I am also hoping you can recomend one or more sources of information on how to test other suspect components in the future in case the TPS checks out ok.
AnswerBrian, I don't know what your issue with the car is. What is the complaint with the car? The TPS is a typical three wire potentiometer (power,signal,ground). The yellow wire should be 5 volt power, Brown is ground, and Black should be Signal wire back to DME. I don't know what the specs are but tipically our stuff is 0-5volts or 0.5 - 4.5volts on the signal wire. Just make sure you have a scope on it or a meter with graphing capability to make sure the resistance change is smooth and that it doesn't have notches or peaks.
-Evan