[gorbypark]

Jeep is horrible. I was gifted a 2007 Jeep Commander, which was Jeep's "answer" to the Hummer. This was in like 2017, so it was 10 years old at that point. Anyways, it wouldn't shift into 4x4 mode, and after some internet sleuthing I found out there was a (now second) firmware update the dealership could do to hopefully fix the issue. I don't remember the exact details, but basically there was a hardware flaw in the module controlling the transfer case, and when it failed the vehicle would go into neutral, which obviously could be quite dangerous depending on where you were parked / what you were doing.

Instead of fixing the actual hardware issue, they did a recall that was some sort of black magic with a firmware update to "fix" the issue. According to the internet, this fix temporarily worked, with pretty much all of them failing again, conveniently after the vehicle was out of warranty.

Anyways, there was a second firmware update, that I had done 10 years after the vehicle was made, that more or less actually "fixed" the issue. Apparently the issue (according to Jeep forums, so take with a grain of salt) was due to some traces being undersized on the PCB, so the fix was to drop the voltage and/or current being sent, and then more or less disabling the safety sensors that would complain about low voltage. After the second firmware update, it would shift into 4x4 about 1 out of 4 attempts (otherwise just failing with "couldn't shift into 4x4" on the screen), and that was the final thing that could be done.

It took Jeep about 4 or 5 years to issue that final firmware update, probably to try and avoid a class action lawsuit over 90% of the vehicles 4x4 system failing just outside of the warranty period!