Changed Tranny cooler lines, tranny went into limp mode

Discussion in 'KJ General Discussion' started by Trailrabbit, Oct 18, 2020 at 9:18 AM.

  1. Trailrabbit

    Trailrabbit New Member

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    Hey guys looking for some advice. Did the tranny cooler lines and new oil pan on my 05 KJ 3.7 (42RLE), everything seemed to go smooth. Pulled out on the highway and it shifted hard into 2nd and stayed there. Check engine light came on and threw 2 codes. P0731, first gear incorrect ratio and P0700 tranny request MIL.

    We can only assume when changing the lines some debris may have been stirred up and clogged something up. Pulled the pan and drained the fluid and refilled. went for a good long drive in the woods in low range hoping it might warm up and clear itself up. No go.

    What should we try next? I'm thinking a new valve body in the tranny. Seems to be a common problem from my searching.

    thx for any suggestions
     
  2. JeepJeepster

    JeepJeepster Full Access Member

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    Have you checked the fluid level with the jeep running in N?
     
  3. Trailrabbit

    Trailrabbit New Member

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    Yes
     
  4. JeepCat

    JeepCat Full Access Member

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    Do you use ATF+4?ok
    Try this: It has to be at operating temperature, in addition to looking at the level in position N, before doing so, move the gear selector to P / R / N / D / 2 / 1, stay a few seconds in each position, then do the same but in the opposite direction, then go back to N and check the level, remember to apply the parking brake.
     
    Last edited: Oct 18, 2020 at 10:38 AM
  5. LibertyTC

    LibertyTC Well-Known Member Staff Member Moderator

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    Did you replace the trans filter, and use ATF+4 ?
    On level ground when driven/warmed up, is the dip stick at the full line?
     
  6. Trailrabbit

    Trailrabbit New Member

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    we did indeed use Mopar ATF+4 and run through the gears a few times to get the fluid circulating. I did actually use up all my tranny fluid the SECOND time we filled it but the fluid level is alnmost at the full marks. I'll grab another jug and tomorrow and rule that out..
     
  7. JeepCat

    JeepCat Full Access Member

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    Make sure you are on a level surface, re-read the manual, it is always helpful to review these tasks.
     
  8. Trailrabbit

    Trailrabbit New Member

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    Got my hands on some tranny fluid and topped it up. didn't make a difference. Starts off in 1st gear after it's been shut off, rough shift into 2nd and there she stays.
     
  9. LibertyTC

    LibertyTC Well-Known Member Staff Member Moderator

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    Jeep dealer has star scan scanner that can instruct new fluid, to re learn new shift points.
    Otherwise u could remove both battery terminals tape them together for 45 minutes and see if that makes any difference.
    Note all previous codes before doing so and note any new codes.
    It can take a while for the trans to re learn.
     
  10. JeepJeepster

    JeepJeepster Full Access Member

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    Did you replace the trans filter? Are you certain the trans filter was seated correctly?
     
  11. Trailrabbit

    Trailrabbit New Member

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    just did the tranny fluid not long ago.. filter still like new. Stopped in to a mechanic that works on jeeps a bit more frequently and he said to try a little lucas tranny fix and mentioned one of the plugs we might have bumped when we jacked the motor to do the oil pan(which we did at the same time as the lines). Ill address that stuff tomorrow and report back.
     
  12. Trailrabbit

    Trailrabbit New Member

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    I got er!!! Sprayed some Caig D5 contact enhancer on both input and output speed sensor plugs. Went for a drive and it’s working mint! Tried a bottle of Lucas earlier today as well with no luck but sometimes that stuff takes a while to work... so technically either of those things could have worked. But, Pretty sure one of those plugs was just dirty enough it lost contact while jacking the engine to do the oil pan.
     
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