Service 4WD-Grand Cherokee L Limited

Sarge said:

It's a ZF sourced transmission, and they generally make excellent products. My wife's 2008 535xi with 165k on it still shifts like the day it came off the line, with only a few issues along the way (solenoids, cheap), with regular 50k mile fluid changes.

Make sure your dealer is using the newest WL-capable scantool (my dealer just got the new tool today, and it pulled a LOT more codes than they were previously seeing). So ask them about that... maybe it will help with the diagnosis.

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TORQUEFLITE 8 (8HP70) SPECS​

Sarge said:

It's a ZF sourced transmission, and they generally make excellent products. My wife's 2008 535xi with 165k on it still shifts like the day it came off the line, with only a few issues along the way (solenoids, cheap), with regular 50k mile fluid changes.

Make sure your dealer is using the newest WL-capable scantool (my dealer just got the new tool today, and it pulled a LOT more codes than they were previously seeing). So ask them about that... maybe it will help with the diagnosis.

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Karmbruster said:

Bought this beauty back in August. Had to take it in a few times for the recalls. Once for a software update for the transmission. Shut off on me at a stop light and automatically kicked on the e-brake. Software update worked and haven't had that issue since. Almost at 6700 miles now, and my service 4wd light just came on. Also been having problems downshifting from 5th to 4th gear. Almost as if it's catching the gear then slipping, causing the car to jerk forward. Taking it in Monday. Hoping it's an easy fix, or I'll be looking into lemon law for the 2nd time now. Fingers crossed its something simple. 🤞🏻

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cmpk13 said:

My service 4wd light cane on about 7 times was only able to get to the dealership 4 times for them to pull the code. Make sure to get to dealership asap every single time or take a pic. Jeep wont recognize this as valid unless a code is actually pulled and dealership opens star and transfer case to check. Ive been denied 5 times w the lemon law. I noticed that when you turn jeep on and off it resets so it’s impossible to fet to the dealership sometimes and if they service it without a code its still not valid. This is how jeep in getting away with it. I had to stop with im doing on my way to work just to drop it off hitch a ride to work from the dealership just to get it probably done.

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SweetAndLow said:

It stores the code in memory even if the light goes away. I think you need a new service department.

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cmpk13 said:

My service 4wd light cane on about 7 times was only able to get to the dealership 4 times for them to pull the code. Make sure to get to dealership asap every single time or take a pic. Jeep wont recognize this as valid unless a code is actually pulled and dealership opens star and transfer case to check. Ive been denied 5 times w the lemon law. I noticed that when you turn jeep on and off it resets so it’s impossible to fet to the dealership sometimes and if they service it without a code its still not valid. This is how jeep in getting away with it. I had to stop with im doing on my way to work just to drop it off hitch a ride to work from the dealership just to get it probably done.

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FlyingAvocado said:

After seeing the photo Rollerbones posted, as a software engineer I feel the need to rant.

If by chance a Jeep Product manager or Software Engineer working on the driverside display should read through this... if there is one take away it should be this:

You already know A full LCD display does SOOOO much more than an analog display - so why does it replicate an analog indicator light from the 1980s? I truly feel terrible for the service technicians which have to figure out what "SERV 4WD" actually means and has to try to explain it to a rightfully angry owner. Jeep ought to treat this indicator like a systems log for a complex distributed system (because that is exactly what vehicles have become) which you personally will have to debug at 3AM. Complex systems _will fail_. What you put into and error message will make a HUGE difference in the time it takes to recover from the issue. With that in mind, for the love of god, PLEASE output a more useful and helpful error message!

Using the pretty LCD in these vehicles to output a detailed and meaningful message which actually tells us the detected problem would be wonderful. Even if customers don't know exactly what the error means, it would enable service technicians at dealerships to improve their service turnaround by helping the customer give the technician a useful and detailed status message from the moment we bring the vehicle in. No need to spend more time to connect an external computer or tablet to decode it - just show it right there, hell give the tech a QR code on the display to direct them to all the documentation they need even - there are so many better ways to do this. It will make us customers FAAAAAR more happy to see an message which helps us understand the problem, and tell the service technicians with detail about than having to just say, "My 'SERV 4WD' "light" came on."

Code:

----------
|  SERV  |
| ERRMSG |
----------

(Yeah, it shouldn't happen on a new vehicle either... but this specific detail about the whole thing is a pet-peeve of mine.)

</end-rant>

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Deere78 said:

But if they made it easier to diagnose then they wouldn’t be able to charge astronomical amounts of money to diagnose the problem. Unfortunately auto manufacturers are in the busy to make money these days. They don’t seem to want the car to last too long. That would cut into new car sales. They want the vehicle built in such a way the owner needs to bring it back to the dealer for service vs a diy or small shop servicing it. It’s a racket that we the customers are trapped in.

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Fdot said:

my car has been having intermittent service 4wd since I got it in September 21. Brought it to dealer for 10k service. Told me I need a transfer case.

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J6L said:

Well sadly my ‘21 Summit L had the “Serv 4wd” idiot light activate last weekend. Along with the idiot light came a ‘clunking’ noise from the drivetrain. I was approx. 150mi from home and wasn’t sure if I would be able to drive my Jeep back home. I noticed the ‘clunking’ noise was in sync as I started out through the lower gears. Once I reached a steady road speed it seemed to settle down. I elected to baby it back home where I had a recall notice for front end bolts waiting for me. (when it rains it pours) I brought my vehicle into the dealership for the three issues. The recall was not done since the dealership did not have the replacement bolts available for my visit. The ”Serv 4wd” light and clunking are in fact connected. The diagnosis is a faulty ‘front axle disconnect module/actuator.” This in turn would cause the ‘clunking’ I heard as the vehicle started out from a standstill. After a mile or two the “Serv 4wd” light would activate. I did notice every time I turned off the vehicle and restarted it later on, the light had re-set and would be off. It was only after putting a couple of miles on the vehicle that the warning light would activate. The dealership informed me that the drivetrain FAD module is on back order. I will follow this incident up at a later date.

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