+ Reply to Thread
Results 1 to 15 of 15
  1. #1
    Registered Member
    Location
    , ,
    Member No: 150266 tinker14bs is an unknown quantity at this point tinker14bs's Avatar
    Join Date
    Feb 2007
    Posts
    24
    Rep Power
    0


    Yes | No

    How to repair a short circuit in TPS harness

    Alright all I need some help. I have been throwing DTC codes P0121, P1643, P1229 for awhile now and can never get them to clear. I was going through the trouble shooting on the JTIS disc and found a problem. The test was

    CHECK THE TP SENSOR SENSE CIRCUIT FOR SHORT TO GROUNDT urn the ignition switch to the OFF position.Measure the resistance between PI06, pin 03 (U) and GROUND.Is the resistance less than 10,000 ohms? Yes-REPAIR the short circuit. For additional information, refer to the wiring diagrams. CLEAR the DTC. TEST the system for normal operation.
    No-INSTALL a new TP sensor. CLEAR the DTC. TEST the system for normal operation.

    My resistance was only 2500. Now how do I fix the short circuit? I looked at the wiring diagram, but am not sure what I am supposed to be looking for. Can someone help? I would greatly appreciate it as right now I can not drive the car it is so bad and the weather is so nice.


  2. #2
    Registered Member
    Location
    , ,
    Member No: 128972 Frogster is an unknown quantity at this point Frogster's Avatar
    Join Date
    Jul 2005
    Posts
    107
    Rep Power
    0


    Yes | No

    Re: How to repair a short circuit in TPS harness

    Mikey,

    I'm not sure what the TPS is (throttle position sensor???) but my first step would be to disconnect the harness from the sensor and remeasure. Is the low resistance value still present? If not it suggests the sensor. Try measuring across the sensor itself. If the value of the wiring harness when disconnected is still low then the wiring harness would appear at fault. Is there any indication of wear at any point along the harness, is it able to contact a grounding point. While I would normally expect much lower resistance if this was the case, corrosion on any exposed wiring will increase this resistance and depending on your multimeter there may not be sufficient measuring voltage to break down this resistance. The other suggestion is that you are seeing a diode effect. Try reversing the measurement probes and see if the resistance increases to spec. It could be that this is all you are seeing.

    Cheers

  3. #3
    Mikey B
    Guest
    Location
    , ,
    Member No: Mikey B's Avatar


    Yes | No

    Re: How to repair a short circuit in TPS harness

    Thanks for the response Martin. The TPS is the throttle position sensor. All the measurements are taken when the harness is disconnected from the TPS. THere are 3 measuremnts that I took and re checked with the same results. The first is to disconnect the negative battery termianl and check the harness between the TPS and the ECU. This resistance was fine. THe second check was to reconnect the battery and turn the key to on and check for 5 volts between the TPS harness pin 3 and ground. This was 5 volts. THe third test was to check the with ignition off the TPS harness pin 3 and ground for 10000 ohms of resistence. I measured 2500 ohms a few times using both probe ends. The JTIS now states to fix the short circuit, but I do not know where to look. I haven't checked to see if the harness was touchingthe ground anywhere. Is this something that could cause the problem? COuld I have a loose ground wire somewhere? Where should I check the ground wires to make sure they are tight?

  4. #4
    Thierry_1500
    Guest
    Location
    , ,
    Member No: Thierry_1500's Avatar


    Yes | No

    Re: How to repair a short circuit in TPS harness

    AFAICS, the suspiscious cable is blue and goes from pin 3 of the TPS connector to pin 11 of the Engine Module (EM11-11). It should carry a tension between 0.5 and 4.5V from the TPS to the EM.

    I'd disconnect the EM, and measure that cable from end to end.

    If there is a short or ground then you must follow the cable route, and try to find where it is... Which should not be too difficult.

    You can also disconnect the old cable and route a fully new cable from EM11-11, to Pin3...permanently (but this is less professionnal), or only for testing purpose, to see if it cures your problem.

    Keep us posted of what you find, thanks.


  5. #5
    Misiek
    Guest
    Location
    , ,
    Member No: Misiek's Avatar


    Yes | No

    I hope this will help

    Hey Mikey,

    This is TSB I found on Alldata.com, I hope it become helpful for you.






















    Best,

    Misiek

  6. #6
    Misiek
    Guest
    Location
    , ,
    Member No: Misiek's Avatar


    Yes | No

    Re: I hope this will help

    Mikey what is your e-mail address? So I can send you scanned document in PDF format, so it would be easier to read than what I have posted.

  7. #7
    Mikey B
    Guest
    Location
    , ,
    Member No: Mikey B's Avatar


    Yes | No

    Re: I hope this will help

    [email protected]

  8. #8
    Registered Member
    Location
    , ,
    Member No: 150266 tinker14bs is an unknown quantity at this point tinker14bs's Avatar
    Join Date
    Feb 2007
    Posts
    24
    Rep Power
    0


    Yes | No

    Re: How to repair a short circuit in TPS harness

    The jump cable from pin EM11-11 to pin 3 still gives the same value of 2500 ohms when it should be greater then 10000 ohms... Any ideas?

  9. #9
    Bad Email Address on File
    Location
    Tacoma, WA, United States
    Member No: 142182 ch193 is an unknown quantity at this point ch193's Avatar
    Join Date
    Jun 2006
    Posts
    1,054
    Rep Power
    0


    Yes | No

    Similarly, Pin 2 to 11-10

    Mike, I'm kinda butting in on the process. It seems from the schematic that possibly Pin 2 and its mate, EM 11-10, maybe are similar, maybe sim. impedances? Have you checked that leg of the TPS?

  10. #10
    Registered Member
    Location
    , ,
    Member No: 128972 Frogster is an unknown quantity at this point Frogster's Avatar
    Join Date
    Jul 2005
    Posts
    107
    Rep Power
    0


    Yes | No

    Re: How to repair a short circuit in TPS harness

    Mikey,

    If you manually rotate the throttle valve while measuring the TBS resistance does it change? The JTIS text implies that the TBS acts like a pot, so the resistance should vary with rotation. Now my guess would be that 10k is fully closed and max resistance, so it should reduce as the valve opens. Thus it could be that your sensor has somehow rotated on the shaft such that it is not at the full resistance position when the throttle valve is closed or your throttle valve isnít fully closed and you are seeing the correct resistance for its position.

    I could go and stick my head under my hood, but since you are already doing this its probably easier for you to answer my questions. How is the TBS and the throttle shaft coupled? Is the TBS easily removable? It appears to just be 2 bolts on the JTIS picture. If so you could take it off the throttle body and do these tests, though it would be good to know first if the sensor resistance does change with rotation. Then if it does and you remove it you could determine if it will go to the full 10k off the body, thus giving a clue as to an incorrect shaft position or coupling to the shaft. Though if it looks doubtful about removal defer on the side of caution. I would hate for you to make it any worse.

    Anyway let us know what you find.

    Cheers,

    Martin




  11. #11
    Mikey B
    Guest
    Location
    , ,
    Member No: Mikey B's Avatar


    Yes | No

    Watch out!!! Jaguar Gremlins

    Well after all the messing and testing I did last night, unplugging and plugging in connectors. SOmewhere along the way my car decided to run great again when I started it up this morning. So I must've had a bad connection or wire touching somewhere that with all the movement is fixed (I hope). This means the Jaguar Gremlins have left my car and will be searching for another one to attack! Be on the lookout!

  12. #12
    Bad Email Address on File
    Location
    Tacoma, WA, United States
    Member No: 142182 ch193 is an unknown quantity at this point ch193's Avatar
    Join Date
    Jun 2006
    Posts
    1,054
    Rep Power
    0


    Yes | No

    Communicable disease??

    Thanks a whole bunch, Mike! And I'm just now watching the story of infectious tuberculosis onboard a passenger airplane!! I'll destroy all our conversations from my computer in the hopes of denying contact!! My car has enough gremlins as it is, without yours!!

    Congratulations on your apparent success!

  13. #13
    Registered Member
    Location
    , ,
    Member No: 150266 tinker14bs is an unknown quantity at this point tinker14bs's Avatar
    Join Date
    Feb 2007
    Posts
    24
    Rep Power
    0


    Yes | No

    Gremlins are back!!! F%$#!!!!!!!!!!!!!!

    The warning lights and codes are back again. Only made it a couple days. Hopefully I can figure it out fast. My backup car (the reliable one to drive when the Jaguar is broken, which has been 3 out of the 5 months now I have had the Jag) is leaking coolant! I can't wait to fix them both and then sell them both and buy something else.

  14. #14
    Mikey B
    Guest
    Location
    , ,
    Member No: Mikey B's Avatar


    Yes | No

    Re: Figured out how to fix all of my problems....

    So after my car was at Motorcars LTD in Dallas, TX for over 3 months of testing, they came back with there is no way to fix the car. They tried everything Jaguar america had said and also Jaguar in England. The only solution was about a 15K to 20K conversion of all electrical that would not guarntee a fix... So I ended up trading it in on a new 07 F150 super crew. I could not be happier with my descion to dump my bomb and take a 10K hit in the 6 months I owned the car. Good luck everyone else with thier cars, hope they don't have the same fate as mine.... PS nobody buy a green XK8 coupe vin ending in 1129 or something close to taht as it cannot be fixed. First time any of the Motorcars LTD places have said they came across a car that could not be fixed. Looks like I was jsut that lucky.

  15. #15
    Registered Member
    Location
    , ,
    Member No: 145873 Dennis07 is an unknown quantity at this point Dennis07's Avatar
    Join Date
    Oct 2006
    Posts
    587
    Rep Power
    0


    Yes | No

    Re: Figured out how to fix all of my problems....

    Somebody, somewhere ought to be ashamed.

    You've helped me more than once on this forum. Much appreciated. Hope you have better luck with the new hardware.

    D.

+ Reply to Thread


Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

     

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
1e2 Forum