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Resistance Reading on TPS---how to

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  #1  
Old 03-30-2008, 05:56 PM
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Nc Resistance Value on TPS---PLEEEEZ HELP!!!

I pulled my TB off and took off the TPS. When i checked the resistance with my DVOM across the connector terminals i got nothing (O.L) My Manual says...

With ignition off, disconect TPS connector. Measure resistance between sensor connector terminals SIG RTN and TP. If resistance readings are about equal to values in table, sensor is ok.

Now, i am getting no resistance value (O.L.) when i probe between SIG RTN and TP. Is this a definate confirmation that the TPS is bad??? I have tried rotating the TPS and that yeilds no different result.

No tables or values are given in the manual which t'ed me off.


Bad TPS???
 
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Old 03-30-2008, 06:56 PM
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20 lookers, no takers???


Anything??
 
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Old 03-30-2008, 07:39 PM
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TPS Readings

Key on engine off:

The sensor should read 0.50 to 1.0-volts at idle . Rotate the throttle to the full-open position and the sensor should increase voltage 4.0 to 5.0-volts. If the TPS reading are incorrect,....adjust it,..... or replace it with a new unit.

Also check the TPS referance voltage. With the ignition on (not running), Install the positve probe of the voltmeter onto the voltage referance wire of the engines harness. There should be approximately 5.0 volts from the PCM to the TPS

These readings are for the Throttle Positioning Sensor (TPS) not the EGR Valve Positioning Sensor (EVP)
 
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Old 03-31-2008, 01:06 PM
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i understand that part, but with the sensor out, if i get no reading (ohms) across the terminals, then the sensor is bad, right???

This thing is an expensive potentiometer, and if the sensors outputs' resistances are infinite (open) then this thing is bad right??

Just trying to justify spending the $70 for a new one.
 
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Old 03-31-2008, 04:24 PM
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If the sensor is not on the throttle body, it may be in a position outside of its normal sweep, giving you the open circuit reading. I did understand that correctly, that the TPS has been removed from the throttle body?
 
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Old 03-31-2008, 05:00 PM
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What range do you have your ohmmeter set at ?? It has to be above 5 K.

Are you sure that you are getting good connections ??
 
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Old 03-31-2008, 06:06 PM
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my fluke meter is auto ranging, and yes the connections are good. I ran the TPS through its range (spun it) and got O.L. everywhere. I am probing the SIG RTN and TP connectors (ive tried them all anyway).

what do you think

thanks for the replies.....oh, yes the TB is off and the TPS is off of the TB
 
  #8  
Old 03-31-2008, 08:35 PM
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Well, if all you say is accurate, I would vote Bad .
 
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Old 03-31-2008, 08:51 PM
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ok, sorry....probably a dumb question.

I'm pretty sure its bad, and i have the TB off so i'm gunna just replace it now anyway. Thanks again for the quick responses
 
  #10  
Old 04-01-2008, 08:44 AM
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I'm going to get a new TPS today, and i'll test it on my DVOM and let you guys know what a new one reads. While i had the throttle body off, i took some time to clean it (yes i know you're not supposed to) but i used seafoam as i figured it wouldn't damage the coating on the TB. The seafoam worked amazing (i did not scrub hard). I just poured some SF on a terrycloth and wiped gently to remove the carbon....seemed to work great. I also noticed that the plates were not springing back shut very fast, so i sprayed some PB Blaster on the return springs and now the plates spring back like new.

Just thought i'd put it out there.

THanks
 
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