Throttle position sensor on prostar

Discussion in 'International Forum' started by bassman_74, Jul 31, 2016.

  1. Heavyd

    Heavyd Road Train Member

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    Highly unlikely. That would require two separate failures. There are basically two types of throttle sensors, ones with idle validation, and ones without. The ones with, once you let off the throttle and are at idle, the ECM looses a voltage signal on that input and would ignore any throttle signal and cause a fault code. For a false signal, you would have to have both a voltage through the idle validation circuit and a a voltage, within signal range, of the pedal sensor circuit at the same time. Highly unlikely to happen. The other style of sensor has a dual sensor signal, one is always exaclty 1/2 of the other. So when you press the pedal, signal one might be 3 volts, and signal 2 is 1.5 volts. Press more and signal one is 4 volts and signal 2 is 2 volts. Idle they are both zero. So for an uncommanded throttle signal you would need exactly the right voltage on one, and exactly half of that on the signal input for the ecm to allow it. Again, highly unlikely.
     
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  3. Randal Kennett

    Randal Kennett Bobtail Member

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    Will a bad throttle position sensor cause a 2012 Durastar to go into limp mode? I know a bad coolent overflow resovoir sensor will. Been battling that problem for months. Now its limping with no active codes displayed.
     
  4. Cam Roberts

    Cam Roberts Road Train Member

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    Highly unlikely all you guys having throttle position failures. When you do have one you just replace the whole pedal assembly. Those assembly’s last for years. When tps goes bad you will get a code for it. Most symptoms are usually delayed foot pedal response or no response. Pull your codes
     
  5. Heavyd

    Heavyd Road Train Member

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    Any throttle pedal circuit fault will cause idle only and a check engine light.
     
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  6. Jjackson86

    Jjackson86 Bobtail Member

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    Heavy D, this is an old thread, but did bassman_74 ever figure out the issue with losing pedal intermittently? Mines doing the same 2010 pro star. Tried checking faults but it says diag codes are not available from EGC.. what is the EGC?
     
  7. Jjackson86

    Jjackson86 Bobtail Member

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    And when I lose throttle, I can back off, then get back in it, then it goes for a bit, but then the same.. sitting at idle fine, but put it in gear, go for 20 yards or so, lose pedal. I can get this thing home I think if I didn’t have to climb 2 bridges. The pedal assembly is right at 500$, trying to get a buddy to bring his conputer, but afraid his computer won’t read the codes because of the light saying diag codes not available fro EGC.. reading you’re posts for a while now, and have had tons of great info from you among others, but what good is a forum if nobody says what the fix was! Thanks for you’re insight
     
  8. Heavyd

    Heavyd Road Train Member

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    Unfortunately, you are right, not too many people are courteous enough to report back what actually fixed it to help build this great community. I have no idea what fixed it for the other guy. The EGC is the "electronic gauge cluster". most of the time, it is a wiring issue. If your friend has a code reader, it should read what the codes are.
     
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  9. Jjackson86

    Jjackson86 Bobtail Member

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    Thanks HeavyD, my guy said it was an inactive DPF. After checking grounds and wires for hours before he scanned it, I found nothing. After he told me the code, I looked at the DPF filter and there are 2 tiny metal lines, they look like brake lines on the side running down from the DPF pressure sensor. One of them was broken completely at the threaded but welded on the stack. Not enough left to get a clamp on it, so it looks like I’ll be going to the dealer to purchase the line and a hose at the top where the heat shield had rubbed a hole in that as well. Can’t find anything on what these lines are even called online, but I’m sure my guys at the dealer can shine some light. Just praying they have in stock. Hoping that this is the fix, but I’m thinking I dodged a bullet and looks like a easy fix. I’ll follow up tmrw after I get the repair done. Thanks again HeavyD and too many others to name for all the priceless insight to other O/O’s like myself trying to make it!
     
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  10. Heavyd

    Heavyd Road Train Member

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    Those tubes are DPF differential pressure sensing tubes.
     
  11. Jjackson86

    Jjackson86 Bobtail Member

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    Heavy D, replaced the DPF sensing tube that was cracked, as well as the lil rubber hose off the bottom of the pressure sensor. Runs great, but still has a hard fault code 1993 inactive DPF. I looked at wires and connectors everywhere and the only thing I found was the plug for the pressure sensor has a couple wires that I could faintly see copper. As I mentioned the heat shield had rubbed a hole in the hose I replaced and it buggered up the wire a bit. I doctored they up with some electrical tape. I read some different posts online where they say the hard fault, you just have to run it, and it will realize the tube that was broken is now reattached and the “circuit” if you will, is complete. Just wondering if the pressure sensors or others have been damaged in the absence of the pressure tube.
    Was wondering if you have ran into this, or could shine some light!? Thanks in advance
     
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