My check engine light came on a couple of days ago and I pulled a code 22 out of the ecm, so I went to check the voltage of the TPS and it is reading as an average .03V and that even after I tried adjusting the position multiple times. I tried getting the reference 5V by connecting the voltmeter to the ground wire and power but it came up with 0V. Anyone know what this could be? thanks

 

Is this tpi or tbi ? The tps gets it 5 volt reference from the ecm through a C14 at the ecm if tpi Gry wire. If this is tbi it is c14 grey wire. you can also check the voltage at the mat/iat the tps gets a the 5v at a splice. There could be damage there. I would check the ecm first It maybe a bad ecm.

 

Thanks for the reply! My engine is a TPI, the way I checked for the 5 volt reference was by putting the ground prong into the ground wire of the tps and the power prong into the grey one, is this correct? also how do I check for a bad ecm? I should note that I'm fairly new to the electronic side of things and most of this stuff goes way over my head so bare with me if I seem clueless

 

The grey wire is the power wire 5v ref from the ecm, check with the key on. You also might want to check the ground connection behind the passenger side cylinder head.

The ecm would have 5v at pin c14 if not I would suspect a bad ecm if the grounds are good.

 

I hate to say it but I'm having troubles finding the ground wire on the firewall . I don't know if this means anything but I turned the key on in the ignition and put the voltmeter prong in the far right pin of the ecm and it came up with 4.95V with the ground prong touching a nut in the door, is that a good sign?

 

the grounds are on a stud on the back of the drivers side cylinder head.

 

it is good that you have 5v at the grey wire. you might need to do a voltage sweep of the tps.
http://www.iroczone.com/2009/10/adju...on-sensor-tps/

 

the drk blue wire is the feedback, voltage will rise when the throttle is opened. check for corrosion at the pigtail on the tps if the tpis sweeps good. the tps should be .54 at idle.

 

not sure what pin you checked voltage at but here is the pinout.

 

I tried the voltage sweep but there was no change in voltage when I raised the throttle, I went back to the ecm and noticed that every pin has a reading of near 5 volts and one that reads 12V but the pin in the top right corner only reads 0.01V

 

not sure what pins you are testing are you sure your vom is on a 12v dc scale? what is the battery surface charge ?

 

if you measure the gray wire at the tps and have 5v and no change through the tps out the blue wire you have a bad tps. You usually I unplug the tps and check for a open in the potentiometer. You will be measuring the resistance between the lower 2 plug on the tps where the blue and gray wire plug in. with the vom on ohm and the pigtail unplugged you can do a ohm sweep you dont want to see any glitches so move the throttle slow. You should be about at 5.0 kv and range down to 2.25 kv. tps are fairly cheap $30-50, get a good brand name , acdelco, standard motors not some autozone cheap junk.

 

It's not picking up any voltage, I tried unplugging the tps and connected the voltmeter to the blue and grey wire sockets and it's reading .03V . Grey wire by itself isn't getting 5V

 

If the car runs and the only issue you have is the code 22 and no voltage on the grey wire at the tps and have checked the grey wire with the key on engine off at the ecm pin c14 and don't have the 5v ref you have a bad ecm. I posted the flow chart and thought that might make the trouble shooting easier.

 

I tried to follow along the flow chart but I'm still new to the terminology of the electric side of things to these cars so it was a little overwhelming and confusing, thanks a ton for your help! I guess I should start looking into getting a new ecm