So I have researched this issue on here a bit, found a few threads, but no solid fix or answer.

Issue: When I'm driving in the jeep, sometimes I'll here a chime/ding (like i left my door open or seat belt off), then I'll see a sudden flash of a light on the dash (could be a check engine/ trac light/ ESC / etc light) followed by the speedo dropping about 20mph then returning to normal.

-It has happened more and more lately.

-this happens at different speeds, anywhere from 35mph to 80, even with cruise control on

-Lately i have noticed that when the speedo drops, I do get a split second loss on power.

-today it even studdered when the speedo dropped.

-there is no codes thrown and no check engine lights.

I brought it into the dealer, they new exactly what I was talking about, said they have seen 4 or 5 jeep jk's come in, in the last month with the same problem.

They have no idea what it is...... They checked the computer for codes and drove it (of course it didn't do it, when they drove it).

They called me to pick it up and said they don't know what else to do. Said if it happens again bring it back. And boom! It happens on the way home.

So I'm hoping this thread will shed some light on this for all of us that have this issue. Maybe someone has solved it, or maybe just good info gets posted that I can bring into the dealer to help out with this.....

Because right now, I'm lost.....

My jeep is 2013 jk 2dr sport.

 

Check the connections to the battery. Make sure they are tight.

If not that, then could be bad wheel sensor or wheel sensor connection.

That's where I would start anyway.

 

Check battery connections, check and push each fuse down in the fuse box, if it is a Rubi make sure the sway bar disconnect is tightly connected.

 

Your battery is dying. Replace it. My JKU behaved strange like this after the battery failed and I jumped it. It's getting whacky power and is confused. Once you reach 2 yrs you are on borrowed time with the battery. Read up on sudden battery deaths. The JKU behaves differently than any other vehicle I have owned with a dying battery. I had chimes, lights, and speedo doing weird things including staying at zero when I was going about 40.

 

+1 to checking the battery conections.. these JK's have the crappiest battery connectors ive ever seen... the negative one esp seems not to fit real tight... that will cause spikes from the charging system into the computers which will give you wierd stuff like that....
-Christopher

 

So last night i went and had the battery checked to see if it was going bad.

Turns out the connections were a tiny bit loose, you could definitely giggle then with your hand. The battery checked out perfect for the test.

So i got home and re-did the way i had the winch power/negative cables hooked up to the battery. And made sure i really got the connection cables to the battery nice and tight and free of ANY movement. Turns out it might have been loose connections after all..... We will see in the next coming days.

Funny thing is, when it first tried to happen, i checked the connections after reading some threads on the issue. I guess i didn't check them good enough.....

 

Glad you got it sorted.

 

Thanks for keeping us posted. Glad you didn't have to spring for a new battery as I suggested. Your time will come, though. Mine was at about 2.5 years.

 

I had the same issue with mine when new. Drive down the road, hit the slightest irregularity in the pavement and "ding" and tach/speedo drop. Tightened a loose ground on the battery and problem solved.

 

My 2015 JK had this EXACT issue. Dealer was no help. I thought about gear I had added since purchase.( lights & winch)
and went back and ran all the cables, re tightening all the connections. Has not happened since in over 2K miles. Hope you have the luck I did.