U0402 code

[Shelly Williams]

After a thrilling off day of being stranded with a Jeep full of groceries, a ride in a rollback and several hours of diagnostic trial and error, with the help of this forum I was able to correct the "safely stop- the vehicle will shut down soon" warning on the dash by moving the N3 to N4. The alternator and both batteries were load tested within normal specs. When we scan it the only code that comes up is U0402. No check engine light and no shifting issues from the AT. Should I be concerned to drive it tomorrow? I have an appointment with the dealership for evaluation ( its still under warranty) on Monday but its my daily driver and I need my Jeep. Thoughts and suggestions are appreciated.

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[Maplecon]

Had this code come up U0402.... my Jeep Jl Rubicon 2021 would shift hard in lower gears every so often, then notice it would shift hard when the transmission temp went fro 80 to -40 within seconds. When it went into negatives, the car would jerk when down shifting or excelerating from stop position. Dealership replacing transmission under warranty. Just took 3 months to happen.... ugg.... Yes, be concerned.

 

[Jeep Wick]

Just had some odd shifting and a cylinder 5 misfire after getting gas today. U0402 came up. I cleared the codes...only 47k the Jeep has been perfect until today. Really hoping I don't need a transmission.

 

[Jeep Wick]

I think I solved this U0402. Wiring diagrams show TCM canbus as violet/white and yellow going to yellow and gray...I moved these on the green star connector in the glovebox to empty slots. Also disconnected and re-seated the large plug behind the right fender liner. This seems to have worked. If it comes back, hard wiring around this is the next step.
Thanks to alphawolff for his posts.
https://www.jlwranglerforums.com/forum/threads/tcm-failure-twice.140530/post-2932119

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