I finally bought a multi meter to calibrate the TPS that I recently replaced on my 98 sedan with d16y7. I am getting some crazy readings that makes no sense. Both red and yellow wires are showing negative readings, how is this possible??? Red wire, -11.52 and on the yellow, -7.16. I do have a CEL on for my iacv which is currently unhooked. Could this be effecting my TPS readings? I don't see how it can be getting negative voltage. Again, the only code my car is throwing is for the iacv, NOT one for the TPS. I do have an oversized battery in the car as well, but I don't think that would effect my TPS. Please does anyone have any insight to why I am getting these crazy negative readings? The car is running super rich and even backfiring some, and I believe it's due to my TPS being out of calibration and I want to get this thing right. Thanks in advance.

 

There is nothing crazy about getting a negative voltage reading. It just means you have the polarity reversed (red probe on ground, black probe on positive). The voltage reading will be the same either way. What is strange is the readings you're getting. Follow the instructions on this link and see if you have better luck.The Official Honda TPS wiring and calibration thread

 

I will certainly try it step by step from this link when it stops snowing. Ugh. But I am posative that my polarity is correct. I checked it several times to make sure it wasn't an error I was making.

 

Well I went through this procedure step by step today, and yet I'm still getting the same crazy negative readings. Any ideas???

 

it may be time for a new tps, mine bit the dust a few years ago.
got a dorman unit that is working great. avoid blox and ebay brand x,
those didnt work out so well.

 

The only way to get "-" voltage readings is for polarity to be reversed. Regardless if your TPS is bad or not, you should be getting 5V between the Grn/Blk and Ylw/Blu wires when the TPS is unplugged. You should be throwing a code if the voltage is any higher.

 

Make sure the leads are plugged into the voltmeter properly. By convention, the black wire is minus (common) and the red one is plus (volts/ohms).

Then put the black lead on ground and push the red one into the back of the TPS connector along with the center wire. Turn the key on but don't start. Move the throttle by hand and watch the voltage change.

 

Thanks everyone for the help, I finally got my TPS properly calculated this evening. To make a long story short, and to save myself embarrassment let's just say I was making a very stupid mistake and not grounding my multimeter properly. All is well now, thanks again .