[Caljur]

Hello everyone -

My WK2 (MY2015 3.6L Flex/4wd) has consistently given me the service shifter warning on start-up for the last month or so. Like IAmTodd, it doesn’t seem to have much impact on driving but it often pings me again when I attempt to engage cruise control - which itself just got serviced under a recall. The most annoying part is that it started just after I went out of the 36k warranty. Have any of you had success getting the shifter replaced under the extended drivetrain warranty?

For the JeepCares folks - I’ve been driving Grand Cherokees for 20 years. Never had so many workmanship related issues as I’ve had with the WK2. It’s a comfortable car and capable off-roader. But something as basic as the shifter shouldn’t be failing after 37k miles.

 

[Caljur]

Thanks Zinner! Great gouge on Foxwell NT520. I’d been looking for a good scanner and picked this one up this week.

Scanner description says: ESM lost communication with TCM on D-PT CAN. Says the DTC is D1 C300. Under different menus it lists U1 1 C300 and U1 1 E300 as the fault but the description is always the same. The fault began at 36800 miles. Anyone know if this is specific to the shift knob or the shift module?

It’d be great if the Jeep Care Specialist would tell me if this system is generally covered under the power train warranty. I move around the country a lot for work and am normally a stranger at every dealership I visit. Not a great position for candid discussions about warranty coverage.

 

[Caljur]

Hello all -

Just wanted to follow up on my service shifter issue.

To recap I started getting intermittent “service shifter” at about 36k miles and continued driving. At about 38k it began illuminating upon every start up and re-illuminated when I would attempt to engage cruise control. I read my codes with a Foxwell NT520 Pro - which works well - and got U11C3 and U11E3 “ESM lost communication with TCM on D-PT CAN.” At about 39.5k the car would no longer shift out of park and I had to get it towed.

D-PT CAN is your dedicated powertrain CAN (D440 and D441 if you have a wiring diagram). There are only two components on the circuit: the electronic shift module and the transmission control module. The ESM and TCM also communicate on CAN-C, which explains why I, and maybe others on this forum, could continue driving for so long. Generally MOPAR tech manuals have you start the repair by searching for a short, then move to diagnosing the ESM, and then the TCM. I didn’t have any shorts and was able to verify voltage to the ESM. Per the MOPAR tech manual the fix in that instance is to replace the ESM.

The ESM is integrated with your shifter and is under you cup holders in the center console. It’s very easy to access and replace. But the repair is nevertheless beyond the range of home mechanics, and not covered under the extended powertrain warranty. Because replacement ESMs are sold without software, you need to flash both the ESM and TCM after replacement. And as you know, flash capability is prohibitively expensive. I don’t have it. So, much as it pained me, I sent the car to the dealership for repair. Replacing the ESM at the dealership cost about $300 more than I could have done it for myself (the part is ridiculously expensive).

Turned out to work in my favor anyway. Diagnosing the TCM is well beyond my comfort zone and it turns out that was failing as well. A good while back I posted about my history of rough downshifting and it’s something that has been intermittent ever since I bought the Jeep, even with several TCM flashes. I’d always been able to trigger the 2-1 bump in a rolling stop. I’m not certain MOPAR would have diagnosed the issue if I replaced the ESM myself because the tech manual has a specific order and an ESM, with power supply, throwing codes is supposed to be replaced. Since they replaced the part themselves, there really was no arguing that something else was going on too. And since the TCM is the only other component on the D-PT CAN, that was the only other part that could be replaced. The TCM is integrated with your transmission valve body -which holds all the solenoids in the transmission. The entire component gets replaced as one. MOPAR replaced the vale body under the extended powertrain warranty. It would have cost close to $2k otherwise.

Happy to report that with a new TCM and valve body, the transmission is running smoother than it ever did before. I tried several times over the past several hundred miles to induce the 2-1 bump in a rolling stop and the jeep just doesn’t do it anymore. I figure I must have had a solenoid issue at the heart of my rough shifting that probably would not have gotten fixed within any warranty had the issue with my ESM not planned out the way it did.

That’s my service shifter story.