SOLVED Please Help! Car won't move/electrical issues

[Not2Late]

Happy Labor Day! Guess what I get to do today... Looking for some help/ideas. Anyone had this happen to them? I have a 2021 Mojave with 40k miles.

Driving home last night, dash lit up and car would not shift. Stayed in gear and I limped it home. Checked codes and got:

• U0101: lost communication with TCM
• P1DB9: Please refer to manual

I have had bad battery (Aux replaced) before which lit some bells and wistles up and figured it was my main battery acting up now.
Cleared the codes and went to bed. Next day, fired right up, no problem. On the way back from picking up a new battery, some new codes popped:

• P1614: refer to service manual

Then dash looked like pictures attached below. I limped home barely - the jeep was stuck in a higher gear. Pulled into the driveway and noticed all the lights were illuminated on the floor shifter "D, P, R", etc. Jeep wouldn't shift into park. Set emergency brake. Tried pulling the emergency transmission release cord as well - no dice. Everything still seemed "energized". The engine shut off, but when I opened the door, the open door chimes kept going, radio played, windows worked, etc. I opened the hood, and there was a noticable "humming" sound. Not something is fried sound, but just that energized sound. Unhooked the main battery (didn't do anything) and then the negative connections on the side of chasis next to the battery (that seemed to kill things).

I researched the codes and they seem to be related to the Transmission Control Module (loss of communication with), loose connections, a wire short, or low voltage (which is why I initially suspected the battery). I rummaged around looking for loose or frayed wires. Also checked the relays/fuses in ther fuse box associated with the TCM.

Went ahead and replaced the main battery since I have it. Hooked everything back up and nothing has changed. Had to unhook all the battery connections again to get it to stop humming. Any thoughts or similar experiences? Anyone know were the TCM is on this thing? Going to take it to the dealer ASAP, but at 40k miles it is now out of the 3/36 warranty period.

Thank you!

Sponsored

 

[Not2Late]

So, I think I figured it out (hoping this was it). Here's what I found in case anyone has a similar problem in the future:

This thread gave me some ideas:
https://www.jlwranglerforums.com/fo...do-not-shift-or-turn-engine-off.104780/page-2

Especially @speedymart's input on a similar issue.

I figured I would start with the "low hanging fruit" possiblities and that would be some sort of loose connection, a critter chewed something, or similar. Here is what I did:

• Crawled around looking for chewed cables. Honesty don't know what is what, but I could at least take a good look at everything I could see from above and below! Everything looked good as far as I could tell.
• Took the passenger front tire and inner fender liner off so I could access the electrical connectors refered to by speedymart (see picture below - took it after I was done. For some reason, I never think of taking the pictures as I am grumbling and swearing in the middle of it)
• I unhooked both connectors and then reconnected them.
• While I was at it, cinched what looked like two ground wires nearby.
• My aux battery had been replaced under warranty a few months ago. I decided to drop it from below to check on it. Looked newer, so good to see that. Checked with a voltmeter. Looked good. But... I was able to tighten the terminal cables quite a bit more than I expected!
• From up top, I was able to tighten a few turns the four bolts inside the fuse box - read somewhere that if that is removed to service the aux battery, sometimes those bolts are not tightened down enough
• Made sure the TCM related fuses and relay were good.

Put everything back to together - and it started!! No warning lights (with the exception of the check engine light) and I could shift the transmission just fine. Cleared the check engine light and drove around for 30-45 minutes. No problems.

Not sure which of the above things I did addressed the issue. If I had to guess, it would be the loose (kind of) aux battery cables or the connectors I re-connected.

Now I just need to hold my breath for a week as I drive around

 

[kevman65]

The bolts inside the fuse box pull the connectors that are underneath up tight to all the fuses and relays.
Since you had multiple issues AND a hummer (if you're old enough you know) I'm going to venture a guess your problem was in the fuse box.

 

[jeepers29]

Happy Labor Day! Guess what I get to do today... Looking for some help/ideas. Anyone had this happen to them? I have a 2021 Mojave with 40k miles.

Driving home last night, dash lit up and car would not shift. Stayed in gear and I limped it home. Checked codes and got:

• U0101: lost communication with TCM
• P1DB9: Please refer to manual

I have had bad battery (Aux replaced) before which lit some bells and wistles up and figured it was my main battery acting up now.
Cleared the codes and went to bed. Next day, fired right up, no problem. On the way back from picking up a new battery, some new codes popped:

• P1614: refer to service manual

Then dash looked like pictures attached below. I limped home barely - the jeep was stuck in a higher gear. Pulled into the driveway and noticed all the lights were illuminated on the floor shifter "D, P, R", etc. Jeep wouldn't shift into park. Set emergency brake. Tried pulling the emergency transmission release cord as well - no dice. Everything still seemed "energized". The engine shut off, but when I opened the door, the open door chimes kept going, radio played, windows worked, etc. I opened the hood, and there was a noticable "humming" sound. Not something is fried sound, but just that energized sound. Unhooked the main battery (didn't do anything) and then the negative connections on the side of chasis next to the battery (that seemed to kill things).

I researched the codes and they seem to be related to the Transmission Control Module (loss of communication with), loose connections, a wire short, or low voltage (which is why I initially suspected the battery). I rummaged around looking for loose or frayed wires. Also checked the relays/fuses in ther fuse box associated with the TCM.

Went ahead and replaced the main battery since I have it. Hooked everything back up and nothing has changed. Had to unhook all the battery connections again to get it to stop humming. Any thoughts or similar experiences? Anyone know were the TCM is on this thing? Going to take it to the dealer ASAP, but at 40k miles it is now out of the 3/36 warranty period.

Thank you!

What is the transmission emergency release cord? Never heard of such a thing.

 

[Not2Late]

What is the transmission emergency release cord? Never heard of such a thing.

It's this thing. Secret compartment and all!!

 

[jeepers29]

It's this thing. Secret compartment and all!!

Well thank you, You learned me something new today.

 

[wkeith67]

It's this thing. Secret compartment and all!!

Never knew about that either. Thanks! As Jeepers29 Said. Learned something new today.

 

[Dp7]

It's this thing. Secret compartment and all!!

I've been using this several times the last few weeks on my JL Dealer hasn't been able to track down the electrical gremlins disabling the vehicle.

 

[joshhallahan]

Did you ever have the issue come up again? I’ve been dealing with this on mine. I have a 2020 Mojave. I’ve done all that you did and more. Replaced z fuse array, replaced both batteries, replaced cambus behind glove box. Still have this issue pop up every week or so.

The reason all the codes cleared for you was because you disconnected both batteries when you were loosening and tightening the z fuse arrays in the PDC box. The computer rest the codes and it takes it out of limp mode until whatever triggers these codes and limp mode turns on again.

Sponsored