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Discussion Starter #1
If you didn't get it from my thread title... I'm trying to figure out how to check the voltage of my TP and MAF sensor. I have a few DTCs (P1100, P1120, P1121, P1125) I just need to know which wires I will be checking the voltage between to see if they are operating correctly (which I'm guessing one or both of them are damaged).
 

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for the TPS ground the NEG of the multimeter to the body and tap the [EDITED] White feed of the TPS harness, turn the car on ( not start it) and you should get a reading of just under a volt slowly hit the throttle and watch the voltage change..

I will reply back with the idle and WOT voltages needed..
 
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Discussion Starter #3
Ok thanks, please let me know. Anyone else know about the MAF?
 

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About the TPS (Throttle Position sensor) you should check if the sensor is loose or not seated right, if the TB plate is closed correctly.

I am going to read my manual to see how the MAF is checked, I will post later about this.
 

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I found the right section in my book. They check the MAF with a code reader in MAF V PID mode monitor. You have to start the engine with the reader plugged in, in this mode, and then wiggle a little bit the connector. If it changes to less than 0.23 volts (minimum) or more than 4.6 volts (maximum), then check and replace wire harness if necessary.

If this is not your problem, then there are a lot of things to check that will take me a lot of time to write here.
 

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Discussion Starter #6
Is that the only way to check the MAF, with a scan tool?
 

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You could always check the resistance but the with a scan tool it's takes 2 minutes. Also your local parts store probably has one they loan.
 

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Discussion Starter #8
Well it looks like I found the (or maybe one) problem... I checked the voltage of the TPS and it's reading 5.02v constantly. No matter what angle the throttle plate is, I get a constant 5v reading. Looks like I will be replacing the TPS first, then we'll see if the problem still exists.
 

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the only way to check MAF voltage is with a scan tool, it's always slightly changing, and with a scan tool you'll be able to know if its bad or not. But if it was bad you would know because the car would run like crap.
 

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don't change it just yet Thats not right... if its at 5volts at idle ( closed) the car wouldn;t start at all

lemme check something quick on something
 

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Discussion Starter #12
don't change it just yet Thats not right... if its at 5volts at idle ( closed) the car wouldn;t start at all

lemme check something quick on something
I tested it with the multimeter just like you told me to... key in on position, engine off, grounded the negative to the body, and tapped the yellow wire of the TPS harness with the positive. I got a 5.02v reading multiple times. Then tried opening the throttle slowly and got no change in voltage.
 

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Discussion Starter #13
Unless I'm tapping the wrong wire (which I'm pretty sure I'm not, since its the only yellow wire, lol) my TPS is not working correctly. I'm going to go to Advance Auto Parts tomorrow and see if they have a new one for me, if not I'll try Pep Boys and NAPA. And if all else fails I can get one on eBay for $23 shipped.
 

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Let me verify with one of my wagons first in the morning... I havn't been feeling well the past few days (still not right now but its better) lemme just retap my TPS and verify this I may have told you to tap the wrong wire and I will feel like utter crap if I did ( Im almost positive it was yellow but the way that you describe it sounds like the voltage feed if its a constant 5v+

tps's usually never deadshort unless it took a dive into a lake they will wear and cause voltage drops/spiked

Give me till around 7:30-8:00am to check...
 

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[slap]
:( I made a mistake yellow is 5.04 voltage supply

WHITE is the wire you need to tap I JUST tapped mine and you were right we at least we know your power to the tps is good :)
 

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not really cus I feel like crap even more now :(
 

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Discussion Starter #18
It's all good... I'll go out and tap the white wire and see what voltages it reads. Any chance you know what voltages it should read (idle, wot, etc) if it is functioning correctly? Sorry your not feeling well, but thanks for checking.
 

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roughly 0.85 at idle (under .9) and roughly 4.50 at WOT (under 5 volts)

go from idle through out the range, slowly open the throttle ( with the car in the on position and NOT running) and watch the voltage slowly rise

heres mine
 
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