Originally Posted by roman
How do I check to see if my tps is acting up? Can I just spray it down with electronic cleaner stuff..like the same stuff used on the mass air flow sensor?
edit: How do I measure the TPS voltage? I have no idea where to rpobe the wires since the thing has to be connected to give me a reading
There'* three wires going to the TPS. One is ground (Pin C), another is a +5VDC reference voltage (Pin A), and the last is the signal going back to the ECM (Pin B). It works just like a **** on a stereo.
You can test if it is OK by unplugging it and measuring the resistance at the connector between either Pins A & B, or pins B & C. When the thing is working right, moving the throttle by hand will cause the resistance to change. Resistance on pins A & C is a constant..it never changes with moving the throttle.
When one goes bad, you usually see places where the resistance goes to infinate as the throttle position hits a spot...this is the bad contacts inside the TPS hitting a dead spot, or the resistance changes in a non-linear manner. There'* no cleaning a TPS sensor out...pitch it in the trash and put a new one on if the sensor isn't reading right.
The units are supposed to be sealed, but as I've found, getting one wet is the kiss of death.
The impact a bad TPS has is pretty straight forward...the ECM has no way of knowing what your right-foot is doing with the gas pedal, or it sees a change in resistance that isn't related to the throttle actually moving to let more or less air into the motor. Drives the ECM nuts while it hunts for a pulsewidth that will keep the motor spinning.
It will not throw a code unless it fails completely (like unplugging it, or an internal short that runs the output signal past 4.9 VDC.)