Hey all,

just thought id share a little something i found today that i couldnt see here. While fiddling under the bonnet, i removed the TPS trying to clean up my throttle body... and that was the moment i realised it was adjustable and needs to be fitted in a very specific spot...

So i scoured the webernets for a procedure to adjust, and while most say to locate a wire on the ECU harness, which would be very impractical to do on your own, this method I found was much much easier. Keep in mind I did this on my MY00 wrx... im not sure if this will work for other models, and if it does you may need to double check the required voltage for your particular sensor.

ADJUSTING AND CLEANING THE THROTTLE POSITION SENSOR.

In order to adjust the TPS the manual says to measure voltage at the TPS by inserting meter probes into the plug at the ECU plug connection. In order to accomplish the feat at the TPS itself, therefore without tying yourself in a knot under the dash, you will require, best of all one of those dress making pins with a nice thin shank and a knob on the end, or a thin needle. Also a meter to measure 0.5 volts d.c..

The TPS comprises a potentiometer, presumably used in a voltage divider configuration, as three wires come from it. There is a plug and socket close to the unit so that it can be easily removed for servicing. At this plug the wires are --- black ground and one end of the resistance element, red the other end and white the wiping contact.

Stick your pin right through the white insulated wire, so that you can clip your meter lead onto it to make measurements. A fine pin will not damage the conductors as they will spread and there will be no significant damage to the insulation. Measure between the wiper, i.e. white wire and ground by connecting to the engine, or battery negative.

If you remove the unit, stick the pin in before replacing it, as it is much easier to do on the bench. Don't forget to pull it out when you have done the deed.

Now from the book :-- 1. Connect all connectors. 2. loosen TPS fixing screws. 3. Turn ignition on. 4. Adjust TPS position, (i.e. rotate the complete assembly), while throttle valve is confirmed FULLY closed, to specified voltage, using a volt meter. 5. tighten fixing screws.

The voltage is specified as within a tolerance of from 0.45 to 0.55 volts. You should have no trouble in setting things at exactly half a volt.

Before removing the TPS or altering the original setting it is a good idea to mark the mating castings with a scratch so that one can check on the adjustment, before and after, as a matter of interest. It is always nice to know if the effort expended has in fact improved things.


Taken from this forum Cleaning the TPS - ---Post up your problems here for some help - SVX Tech - Subaru SVX World Forums