In the past 4 weeks I have gone through 2 brand new TPS sensors from Pep Boys. Both were code P0123. They warranteed the first one as defective and now the 2nd one has failed. I have so far added it's own ground to the firewall and am reading 1/4 Ohm at the plug and I'm getting 5v to the sensor. Before I go and replace it again, could it just be that I'm unlucky or could something else be the culprit?

(I will be buying mopar sensors from now on!)

 

Sounds like you have a meter. Have you measured the voltage while moving it through it's range of motion?

 

Isn't it supposed to be a 5 volt signal?

 

Three wires. 5-volt supply, ground, and the output signal voltage varies based on throttle position.

 

This is the only test I haven't done and will do soon!

 

Analogue meter would be best, observing the sweep is simply a lot easier that way
Bought a cheap one of eBay ages ago just for this test.

 

So does anyone think that getting 2 defective TPS's in a row is even possible?

 

If they're el-cheapo "Made in China",... yes... absolutely possible.

I would definitely check the wiring and do some testing however. There may be something else that can make that code trigger that might be worth looking into.

 

I have a Mopar IAC on the way and if I can get Pep Boys to refund the 2nd defective one then I'll order one from Mopar.

 

I got pep boys to give me a full refund and am now waiting on a Mopar TPS to get here. I'll take some new readings then and pray!

 

That wouldn't be the first time it's happened.
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Question, while I'm waiting for the Mopar TPS I decided to poke around a bit. I have 4.72v coming from the middle pin and 5.17v coming from the outer with just the ignition on. I wasn't able to hook up the leads to do the sweep test but what does this alone tell me?

(I hate these fkn sensor issues!)

 

Is this with the sensor plugged in? If it is, and the ground connection is good then the sensor is likely bad.
Pin 1 - Brown/Yellow wire = ground. Should be pretty close to zero. Measuring the harness side while the sensor is disconnected, you should have 0.25 ohms to ground or lower.
Pin 2 - Orange/DarkBlue = Single wire. Should sweep fro low to high as throttle is opened
Pin 3 - Orange = +5-volt power.

If this wasn't with the sensor connected, plug in back in and retest.

 

This was done with the sensor Unplugged!

Pin #2 (middle pin of plug) is showing 4.72v and pin #3 is showing 5.17v with just the ignition turned on.

 

So, as lawsoncl said, repeat with sensor plugged in