Throttle position sensor

[NAJ]

I cannot honestly answer the question of reliability. It has been on the car since April with no problems and with the one year free replacement warranty I had nothing to lose.
I could have ordered a Mopar at work but the check engine light was on and I did not want to wait at least 1 day if it was in the local parts depot(Newark De.), if it was only in National it could have taken 3-5 days.

[Diablo]

my car has run great for about a month or so and now its back to throwing the 24 code!! when i took the muffler off it stopped all together. that was about 3 or so weeks ago. yesterday i plugged a vacuum leak and it started again. i put it back how it was and its still throwing the code. ive rechecked the wires and even pulled the ecu to see if it had some signs of failure but found nothing. the board is covered in that gel crap so i cant see the solder joints. could this be an ecu issue? something else?

thanks
diablo

[NAJ]

You are going to have to start from square one and diagnose the code.
First determine if the code is a high or low voltage code.

[Diablo]

how do i determine that

[NAJ]

If you do not have a scanner which will give you the description then you will use a voltmeter.
Testing the TPS circuit is fairly simple.
With the key on engine off backprobe the TPS connector signal and signal return wire while it is still connected to the TPS. That would be the BK/LB and OR/DB wires.
What is the voltage reading? above 3.50 volts? below .40 volts? If the reading is between .40 and .90 slowly sweep the TPS and watch the voltage, does it rise consistantly as the throttle is opened or did it drop off at any point? If it dropped off at any point during the sweep replace the TPS. If voltage is high/low......
Disconnect the TPS connector,with the key on/engine off with 1 lead of your voltmeter connected to a good ground probe the VT/WT wire with the other lead, does the meter read 5 volts? If no repair the 5 volt reference line, if yes....
Probe the VT/WT wire with 1 lead and the BK/LB wire with the other lead, does the meter read 5 volts? If no repair the signal return line, if yes.......
Check continuity on the signal line from the TPS to the SBEC cavity # 22, this is the OR/DB wire, if resistance reads over 5 ohms repair the signal return line....
If resistance is below 5 ohms connect 1 lead of the ohmmeter to a good ground and probe each end of the signal line with the other probe, does the ohmmeter read open on both ends? If no, repair signal line short to ground, if yes, replace the TPS.
Be aware that the terminals break/crack inside the TPS connector, and be sure the terminals are not spread open or pushed out.

[GLHExorcist]

...Out of curiosity Naj, (or anybody else for that matter...) would a bad tps cause a part throttle missing condition? By missing, I mean when I drive the second it sees moderate boost (7 to 12 psi) if not at wot it chugs and spews thick black smoke. If I plank it, the miss goes away with a loud black pop and then it pulls like a banshee.

Sounds like a tps to me, but no 24.

[crazymadbastard]

Quote:

Originally Posted by detobias then I recommend this book ; great resource and written for a TD'er :) Amazon.com: How to Tune & Modify Chrysler Fuel Injection (Powerpro): Ben Watson: Books

Why for a TDer? does it come with a free hep?

[NAJ]

To be sure sweep the TPS while watching voltage and see if it drops off but it sounds like it is loading up during closed loop operation. WOT is closed loop but a fixed controller program.

[GLHExorcist]

...could be.... It's worse when it's cold. At first I thought it was a bad coil, but then it would do it at any throttle position.

[alangentry07]

Hi all, I have code 34 as well. I tested the wires the other day by grounding in the middle and putting the other probe into each other side. One side came up at 4.5V the other was 0, is this what they are supposed to read? I tried to "un-snap" the wire harness part but it didn't open up like I anticipated it would, I'm not sure how I would get inside the black plastic to check the connections. I don't want to start shaving away the sheathing to the wires to test. Has anyone changed the entire TPS wiring part before?

[NAJ]

I am assuming since you posted in a TPS thread you meant code 24, not 34.
There are 3 wires on the TPS.
5 volt reference, signal and signal return(ground)
With 1 lead of the voltmeter connected to ground and the TPS connector unplugged and the key on probe the 5 volt reference line(VT/WT wire) it should read 5 volts if ok probe the reference line(VT/WT) and signal return line(BK/LB wire), you should read 5 volts, if ok that part of the circuit is good. To check the connector terminals wiggle the wires at the connector end and watch the voltmeter, if the problem is a loose/broken terminal the voltage will change/drop off. If ok......
Reconnect the TPS connector and backprobe the signal(OR/DB wire) and signal return lines (BK/LB wire), what is the voltage? With the throttle closed it should be in the .40-
.80 range, if not ok replace the TPS, if ok slowly sweep the TPS and watch the voltmeter for a drop off of voltage, if you see the voltage drop off replace the TPS.
Also be sure there is no corrosion on the connector terminals or none of the terminals are opened or pushed out.