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2015 Trailhawk issues

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2015
13K views 21 replies 11 participants last post by  Desert Hiker 
#1 ·
I have a new 2015 Trailhawk with stop-start and 4:08 gearing. It has 1500 miles on the clock. I love this vehicle, but I have noticed a few issues and wondered if anyone has seen the same issues.

1) radio changes from FM to AM within the first 30 seconds of starting the engine. This happens when still in park, no hands on the wheel, just me in the seat and looking at my cell phone. Never happens again with key on.

2) NO 9th gear EVER.. ( I have tried fast, slow, up hill, down hill, cruse on, cruse off, manual shifting and in "D")

3) NO 8th gear when the cruse is ON, it just hums along in 7th for mile after mile at about 2250rpm @ 70 MPH [MPG at 19 on flat ground]

4) With cruse OFF, I can get 8th gear on flat ground, 70 mph, but I must tip into the throttle, then let off to get it to shift. It will hold 8th till the slightest incline then back to 7th. [8th shows about 1850 RPM and 24 MPG]

5) At highway speed, with 4x4 set to AUTO .. I get a LOUD nosy rumble with noticeable vibration in the rear of the vehicle when a) move the shifter left from "D" to manual. [OR] b) hit the traction control button. I suspect the rear axle kicks on, but why?

Note: 1st through 7th gear shift fine, but as other have mentioned, I have noticed a "speed up" feeling when it down shifts.


I have not talked to the dealer yet, but I will visit in the next week or two.

Any input will be appreciated. Thanks for looking...

Newbee
 
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#3 ·
Yea issue one is a mystery to me, sound like a head unit issue.

The rest of it I haven't seen and I'm approaching 1000 miles. I also haven't touched the "manual" process. From what I've read, it does more harm than good.
 
#6 · (Edited)
I have a 2014 TH with 9,000 miles on the clock and have had zero issues to date.
Your number (1) issue sure appears to be a problem with the radio head as another poster has said.
I have only seen 9th a few times and that is always on a very flat stretch doing over 80 MPH.
I would give your transmission some more time to "learn" your style of driving, I truly think you will see improvemnt.
As for the rumble/vibration i would suspect a problem with one of the tires being either out of round, out of ballance or a broken belt in one of them. There should be no noise at all. You do have to realize the Firestones do have and aggresive tread pattern so you will get some road noise compared to say a Michelin Tour that would come OEM on the Limited.
This is my 7th Jeep and I think they have done a superb job creating the new Cherokee. best of luck.
 
#7 ·
@one_rusty_jeep - I have not had any of the issues 1 - 5. Today I noticed about 1600 RMPs at 59 mph and checked - it was in 8th gear. I can get mine to hit 9th at 80+ mph either going downhill or flat with a tail wind. I'm at 2600 miles.
 
#9 ·
Thanks for all the feedback everyone !
Update with more driving: 8th gear does hold when I drive about 60mph, but still drops out at 70 mph or over .. I typically drive 72 -73 max. Driving 80 to use 9th gear .. hmmm seems like a speeding ticket.

I will also update this post with any information I get from the local dealer.
 
#10 ·
Don't understand why a transmission would hold 8 at 60 but drop out at 70+ unless catching a head wind or going uphill.

A number of states have 80 mph speed limits in sections. Also, the KL was built as a global car so 9th gear might be useful on autobahns.
 
#12 ·
From TFlcar by Chad Kirchner:

"I reached out to Chrysler to see about 9th gear and what conditions the Cherokee would use it. Eric Mayne, Media Relations Manager for Engineering and Powertrain told me that the vehicle is constantly analyzing the current conditions and will use 9th gear if necessary, though it’s not that often. One thing he did point out is that using nine gears allows the engineers to have a 9.81 gear ratio speed overall, which helps them eek out fuel economy and still be an effective off-roader. So even though you may never see 9th gear (and believe me, I tried), it’s still being used by the engineers for overall performance."


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#14 ·
There's a 9% 45 mph downhill going out of town where I live and I moved the shifter over and held it forward like the owner manual instructs for engine braking. It was probably in 6th or 7th gear at the top of the hill and got bold and decided to pass the 5-4 boundary. I think it went down to 3rd. The computer revved the engine to enable the dog clutch engagement and I thought this is not doing much engine braking. But it didn't take too long and the engine braking did its job. I can see why some are alarmed at the downshift when involving the dog clutch. Just takes some getting used to; and use of the service brakes if the circumstance warrants it.
 
#15 ·
We've got issues 1-4, same at you. After our last transmission flash, mileage dropped from 16-18 down to 15-16. I've never gotten anywhere near the 19-27mpg the EPA rates the vehicle for, even on the freeway.

We're back in the dealership for another transmission flash today.
 
#19 · (Edited)
9th gear will hold on any road untill 80 mph after that it will fall to 8th gear.
If i set cruise control in 8th gear it will stay in and when going up a hill on the freeway if the speed drops to far from the trans settings it will dropped to 7th untill the speed builds back up to the trans setting for it to shift into 8th gear. From what i have seen from the trans setting it will drop a gear if the rpm falls below 1500 in the gear its in with cruise control on or off. Now in sports mode on the freeway it will stay in 6th gear and you have to be going at least 80 mph for it to go into 7th gear as it seems the trans settings like to keep it at least 2 gears lower than auto mode does. It all in the trans settings from the rpm. This is why i drive in sports mode in town and as soon as i get on the freeway i go back into auto mode as it saves me about 1.2 mpg overall.
 
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