A year and a half ago the MIL light went on for a TPS problem. I ordered a TPS on ebay and just replaced the old one with this one. The MIL light went away.

A few weeks ago the car a 2000 Integra Type-R failed smog. I decided to look at the TPS sensor while troubleshooting the smog problem.

When I hook up a multimeter and intercept the the RED/BLACK cable going back to the ECM from the TPS the voltage goes from .1 closed to .75 at WOT when I move the throttle by hand. This is with the ignition in position II.

I've checked the sensor by rigging it up with three 1.5 volt batteries and it works fine. No breaks in continuity. And it passes the two resistance tests in the Service Manual.

I checked all the wires going back to the ECM, the ground that goes to SG2, the variable RED/BLK that goes to the TPS sensor input, and the constant 5V wire from the ECM. They all had a resistance of .5 ohm or lower. And the multimeter reads 5 volts from the ground to the constant voltage wire. So I know the sensor is getting power.

The multimeter was calibrated for the resistance tests and yes I know how to read the values off it .

The only thing I can think of now is that something is wrong with the ECM. Could it really be the ECM though? The MIL light stays off and the car runs fine otherwise *scratches head*

 

I think you are doing it wrong. Do not disconnect it. Get a pin and backprobe the connector. On the DVOM black to chassis ground/Batt- preferred. probe with the red lead.

One wire should read 0v One should read 5v and the last is the varible with key on engine off it should be around .75v to 1v then move the throttle and hope the volts go up.

It sounds like you have a good grasp on electrical. Just wanted to make sure..

If you still are having problems run an extra ground wire to the tps ground.
Won't pass smog this way (Visual)but it is a good check for ground.

 

closed .5, WOT 4.5 sensor should be connected when doing this. if readings are off maybe try to turn.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by postman &raquo;</TD></TR><TR><TD CLASS="quote">closed .5, WOT 4.5 sensor should be connected when doing this. if readings are off maybe try to turn.</TD></TR></TABLE>

I tried that but, I just don't get anywhere close.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thesmogman &raquo;</TD></TR><TR><TD CLASS="quote">I think you are doing it wrong. Do not disconnect it. Get a pin and backprobe the connector. On the DVOM black to chassis ground/Batt- preferred. probe with the red lead.</TD></TR></TABLE>

Yeah I haven't done this. I get an image of smoke billowing out of the ECM when I think of it. So the sensor ground really is just a glorified tap into the main ground to the battery? I wasn't sure myself so I haven't had the ***** to probe anything on the ECM.

 

as long as you're just using a meter you can not harm anything on the ECU.
It's not made of glass.

BTW a multi-meter set to voltage will not damage any circuit on a car.

 

I guess I don't really have much to add here, but yeah, if you have a really low output, then either there is something pulling the output down or the 5v supply down, or the tps is defective. If you disconnect the signal wire at the tps and measure the output right there at the sensor with the 5v (check this too) and ground still connected, that will give you a better idea of what is going on.

 

thesmogman, and Relic1 thank you!

So probing the ECM connector RED/BLK TPS variable input using the battery ground the multimeter reads the correct voltage range ~.5-4.5. I wanted to love punch the car. Goes to show that you can't just read the voltage on one wire with a multimeter.

The sensor is a little bad, (the interval was .45-4.2) but I set it up to read well for the SMOG test, which I figure is done with the throttle at about 30% or so. Time to duel with the ebay snipers for another sensor I guess.

 

TPS sensors need to be adjusted when installed.