[brian.jeep]

My 2015 Cherokee Limited 3.2L with ActiveDrive II will not go into low range. It fails during the process. It has also been periodically displaying an error message about servicing the 4wd system and displaying the Svc 4wd light. The local Jeep dealer said we needed to replace the rear differential, but won't guarantee that will fix it. I don't understand what the rear differential has to do with low range which is handled by the PTU. A differential repair shop also said it wouldn't be a differential problem. I called Jeep customer service and they suggested going to another Jeep dealer. This vehicle was recalled for a PTU issue in 2020, but only involved a software update, not a PTU replacement.

Am I on correct that a low range problem wouldn't be with the rear differential?

I'm planning to take it to another Jeep dealer for diagnosis. Any other suggestions on how to get this resolved? I believe the warranty on the PTU is extended to 100k.

Thanks!

 

[Flybynightcru]

My 2015 Cherokee Limited 3.2L with ActiveDrive II will not go into low range. It fails during the process. It has also been periodically displaying an error message about servicing the 4wd system and displaying the Svc 4wd light. The local Jeep dealer said we needed to replace the rear differential, but won't guarantee that will fix it. I don't understand what the rear differential has to do with low range which is handled by the PTU. A differential repair shop also said it wouldn't be a differential problem. I called Jeep customer service and they suggested going to another Jeep dealer. This vehicle was recalled for a PTU issue in 2020, but only involved a software update, not a PTU replacement.

Am I on correct that a low range problem wouldn't be with the rear differential?

I'm planning to take it to another Jeep dealer for diagnosis. Any other suggestions on how to get this resolved? I believe the warranty on the PTU is extended to 100k.

Thanks!

Could be either the RDM or the PTU, both, or if you're lucky, just a loose connection or something. The first thing you need to do is find a competent technician to analyze the situation correctly. That unfortunately is the hard part nowadays. Get a second, third, or tenth opinion if that's what it takes. I'm assuming you don't have any extended warranty like Max Care???😎

 

[brian.jeep]

Could be either the RDM or the PTU, both, or if you're lucky, just a loose connection or something. The first thing you need to do is find a competent technician to analyze the situation correctly. That unfortunately is the hard part nowadays. Get a second, third, or tenth opinion if that's what it takes. I'm assuming you don't have any extended warranty like Max Care???😎

Thanks! No extended warranty. I just recently bought the vehicle used.

 

[AtlCade69]

Find out if there was ever the same issue on the Jeep before you bought it. (especially if it was from a Jeep/CDJR dealer)
Might be a reason they sold/traded it in.
If someone sold it to you knowing about it, but didn't disclose it, they could be on the hook for it...

 

[benjeepers]

You need to find out the code that the Jeep is seeing. The dealership could potentially be correct.

If the rear diff reaches a temperature the computer deems too high it will not go into 4x4 low and reject the shift command.
the service 4wd code however makes it seems that there is a fault somewhere.

 

[JFlabitz]

The way I understand how the system works, is that both the PTU and the RDM need to shift up or down together to give you high or low range.
The reason they did it that way is to eliminate the drag of a spinning driveshaft assembly when the vehicle doesn't need all wheel or 4 wheel drive.
In other words, it disconnects at both ends via the PTU and the RDM to maximize efficiency when 4 wheel drive isn't needed.
How much that helps, I don't know, but it sure adds complexity.