Location of Throttle Position Sensor on 2012 270SLX Mercruiser 350 MAG 5.7

Discussion in 'Electrical Stuff' started by 270SLX2012, Apr 5, 2021.

  1. 270SLX2012

    270SLX2012 New Member

    7
    Jan 2, 2021
    2012 270 SLX
    350 Merc 300hp
    Hoping some of you who have been down this path already could help out a noob TPS wrangler with some advice. I need to change the TPS. I already have the new part with it's little blue o-ring in hand. I looked everywhere and read every thread and watched every video I could find. I cannot locate where the part is on my boat. I removed the flame arrestor from my engine hoping to see a Throttle Position Sensor somewhere below it to yank out. Cant locate it. Is it on the engine, or is it on the throttle assembly up at the helm? I tried removing the throttle assembly and it's not quite straightforward to remove, in order to get behind it and see if the sensor is back there somewhere. Figured I would post here for some guidance before I go crazy. Thank you! The tender is a 270SLX who first set sail in 2012. Mercruiser 350 MAG 5.7L 300hp
    Thank you!
     
  2. Espos4

    Espos4 Well-Known Member

    Jan 1, 2017
    Long Island NY
    2007 240 Sundeck
    350 MAG Bravo 3 W/DTS
    Do you have DTS?
     
    270SLX2012 likes this.
  3. 270SLX2012

    270SLX2012 New Member

    7
    Jan 2, 2021
    2012 270 SLX
    350 Merc 300hp
    I am pretty sure it is digital. I could not locate a cable running to a throttle body. Hence part of my confusion and frustration. Thank you so much!
     
  4. Espos4

    Espos4 Well-Known Member

    Jan 1, 2017
    Long Island NY
    2007 240 Sundeck
    350 MAG Bravo 3 W/DTS
    DTS Digit Throttle and Shift has the TPS located inside the throttle body. It is usually not serviceable as a separate item.
    What issues are you having that you want to change the TPS?
     
    270SLX2012 likes this.
  5. 270SLX2012

    270SLX2012 New Member

    7
    Jan 2, 2021
    2012 270 SLX
    350 Merc 300hp
    My gauge scrolls a message by that tell me its got an issue.
     
  6. Phil S

    Phil S Active Member

    252
    Oct 16, 2020
    Massachusetts
    2004 300DA
    5.0 Merc B3
    A TPS is on the throttle body, because it has to tell the ECM or engine computer about the current position of the throttle plate inside the throttle body -- even if it's a newer "drive by wire" system without a throttle cable. My engines are from the dark ages when they still had throttle cables :D But I recently had a TPS go bad in my new Silverado where there is no throttle cable. And like @Espos4 said, in that case it's likely not serviceable so you have to replace the whole TB unit. Where did you get the new part?
     
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  7. 270SLX2012

    270SLX2012 New Member

    7
    Jan 2, 2021
    2012 270 SLX
    350 Merc 300hp
    Yeah I read another thread I think where you mentioned that Phil, during my RTFM'ing before posting this thread. How frustrating that must have been for you.
    I bought the suspect part from our trusty friends at Amazon:
    [​IMG]

    Probably the wrong part eh? No user serviceable parts in my throttle body you guys think?
     
  8. Phil S

    Phil S Active Member

    252
    Oct 16, 2020
    Massachusetts
    2004 300DA
    5.0 Merc B3
    That definitely looks like the mercruiser mpi TPS! Here it is the TSP below in an older engine, after you take off the plastic cover (number 2 in the diagram). Do you have one of these?

    upload_2021-4-5_17-34-27.png
     
  9. Phil S

    Phil S Active Member

    252
    Oct 16, 2020
    Massachusetts
    2004 300DA
    5.0 Merc B3
    upload_2021-4-5_17-36-12.png
     
  10. 270SLX2012

    270SLX2012 New Member

    7
    Jan 2, 2021
    2012 270 SLX
    350 Merc 300hp
    First of all, thank you very much for trying to help me and for for taking the time to pull that up and post it here. I had actually found that as well, however my boat does not have the sensor in that location. I think the part I bought would be the part that goes in such an engine, but mine is different. I think it's safe to say at this point that the sensor is in the throttle body. Seems I might need a whole new throttle body huh? Sounds crazy if you ask me that it was designed like that without a changeable vulnerable part found inside it.
     
  11. Phil S

    Phil S Active Member

    252
    Oct 16, 2020
    Massachusetts
    2004 300DA
    5.0 Merc B3
    Ok, do you have a picture of the engine? (especially with the top cover removed)

    Does it look like this?

    [​IMG]
     
  12. Espos4

    Espos4 Well-Known Member

    Jan 1, 2017
    Long Island NY
    2007 240 Sundeck
    350 MAG Bravo 3 W/DTS
    What is the exact message that you get?
     
  13. Espos4

    Espos4 Well-Known Member

    Jan 1, 2017
    Long Island NY
    2007 240 Sundeck
    350 MAG Bravo 3 W/DTS
    For a reference, look up 2010 GMC Savana 1500 5.3 V8 on Rockauto.com

    under Fuel/air click on “throttle body”

    Does yours look like to GM part # 2173151?

    1F010722-AB84-41FF-AAA5-5FF1D8ACC545.png
     
  14. Espos4

    Espos4 Well-Known Member

    Jan 1, 2017
    Long Island NY
    2007 240 Sundeck
    350 MAG Bravo 3 W/DTS
  15. Espos4

    Espos4 Well-Known Member

    Jan 1, 2017
    Long Island NY
    2007 240 Sundeck
    350 MAG Bravo 3 W/DTS
    Any update?
     
  16. Phil S

    Phil S Active Member

    252
    Oct 16, 2020
    Massachusetts
    2004 300DA
    5.0 Merc B3
    If the TB looks like the one Espos4 posted, I believe you can change out just the TPS. They must sell it on Rockauto. It's held on by spring clips unlike the older style that bolted on.
     
  17. Phil S

    Phil S Active Member

    252
    Oct 16, 2020
    Massachusetts
    2004 300DA
    5.0 Merc B3
    TPS:

    [​IMG]
     

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