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2014 WK2
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Discussion Starter · #1 ·
Ha, this is what I get for posting glowingly about my 2014 ecodiesel in a reliability thread :ROFLMAO:. About a week ago my selec terrain module stopped working; no status lights on the module, no response/acknowledgement of terrain mode select, can't switch into 4lo, flashes a message about "completing neutral shift" on startup. Notably, my toddler loves to spin the dial and mash the buttons on this particular controller. Here's what I've done so far on diagnostics:
  1. Use AlfaODB to check 4wd and transmission modules for fault codes; none are stored (see pic 01).
  2. Use AlfaODB to check status of other modules. Body Module reports U1207 - Lost Communication with Terrain Switch Bank Module, with start mileage consistent with onset of issue. Interesting (see pic 02).
  3. Use AlfaODB to check out state data for transfer case / 4wd systems. Looks like I'm in full time / auto 4WD and although I am not familiar with these readouts, nothing looks alarming (pics 03 & 04).
  4. Use AlfaODB to watch behavior of transfer case while accelerating moderately hard on wet pavement during rain. It looks like the transfer case motor is actuating the clutch at the times I'd expect it to (pic 05).
  5. Disassemble center console to access selec terrain connection to power and bus. From the female harness I found that the switch is receiving 10.9 volts DC, which seems a bit low but the engine wasn't on at the time (pic 06). The ground wire and female receiver on the bus side are a tiny bit loose, but in relation to the plastic harness and not each other. The pins coming out of the selec terrain module are very long and should guarantee a connection even with the slight travel of the ground receptacle. I don't think I have a ground fault, and tested the switch in other ways (see 6 and 7 below).
  6. Remove switch and connect to bench power (pic 07). Not sure what I was expecting, was hoping to see some of the status lights come on to give me some idea of whether the switch unit is alive. Nothing happened, but since the switch needs to know all of its state from a module (the transfer case control module?) I'm not really surprised by this. Anyone know differently? Should I have seen a fault pattern flash on a good switch if it came on without a bus connection?
  7. Use 12V outlet in armrest to power switch and connect serial line. I was curious if a different power source and the data connection would get me anything, and I'd noticed earlier that the 12V outlet under the armrest was supplying 13 V with the engine on. No response from the selec terrain unit.
So, my working theory at this point is that the selec terrain switch is dead. However, based on my research it seems like I also want to consider some sort of issue with delivering signals on the bus, or an issue with the Transfer Case Control Module. While looking into my nonresponsive terrain selector, I also realized that a clicking I've been hearing right after starting the vehicle or sometimes after shifting between D and R is actually the transfer case motor. It sounds like this is potentially benign, but might go away if the Transfer Case Control Module is replaced.

I'm hoping a tech or someone with a similar level of experience can help me answer the following q's to help with my decision making:
  1. Should the selec terrain panel have done anything when supplied with power but no data connection? Flashed status lights, etc.
  2. What does the communication loop between the selec terrain switch, body computer that runs the dashboard displays, and transfer case control module look like? I assume the selec terrain panel sends a message when a mode is selected, but receives back its displayed state from the transfer case module, and the body computer is getting state from the switch to display a mode change or the 4lo light. Otherwise, how would the body computer know that the switch is unavailable/down in order to throw U1207. Is that correct?
  3. Is noise/interference on the bus a possible culprit here? Beyond being in the realm of the possible, is it at all likely?
  4. What's the best Mopar parts site to order replacements from?
 

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Registered
2014 WK2
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47 Posts
Discussion Starter · #2 ·
I tried replacing the Transfer Case Control Module first based on my theory that the switch is probably pretty dumb and just relaying what it gets from the TCCM to the Body Computer.

This fixed the cyclical clicking from the transfer case when stopped or after switching between D/N/R, so I seem to have solved another problem. Based on other reports of replacing the TCCM to fix clicking or more serious issues, I'll probably experience smoother on pavement driving. However, the Selec Terrain module is still dead. So, ordering a new switch next.

I ended up paying the dealer a lot more for the module since they had it in stock and I was in for the EGR recall today. The parts department confirmed that it is a plug and play install, no calibration or flashing, and it took me five minutes at home. I couldn't get returned calls or emails to tell me if any of the Mopar wholesalers actually had it in stock. And, FedEx shipments are currently often delayed a week plus due to staffing shortages at the local distribution centers. Getting reallllllly tired of Covid times.
 

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Discussion Starter · #3 ·
It was the transfer case switch, or what most of us probably refer to as the selec terrain module. For anyone with a similar problem, here is what I've learned from my experience and hunting down every thread on similar 4wd issues:
  1. If your selec terrain switch is totally dead (no status lights at any point during startup or operation), you are getting a message about "completing neutral shift" on your display during startup, and you are reading U1207 - Lost Communication with Terrain Switch Bank Module from the Body Module, your likely culprit is the switch. I replaced my original switch, part # P68141344AC, with an updated but compatible and externally identical version, part # P68258737AA. Ran the new switch through all its paces in my driveway, including 4lo, and everything is good.
  2. If your select terrain switch is flashing an odd pattern on startup and you're seeing an error from the 4WD Module in your code scanner, your issue is likely the Transfer Case Control Module or the transfer case itself. I did not experience this fact pattern, but I did find a lot of threads about inoperable 4wd controls that did.
  3. If your transfer case motor is clicking (rapid sound from under the driver's side middle), replacing the Transfer Case Control Module will likely fix that. It seems like this issue is benign, at least until all the unwanted cycles wear something down. I only became aware that mine was doing this while researching the dead switch. Although it was not a cheap part and not the culprit, I'm glad replaced the Transfer Case Control Module to avoid problems down the road, and because hard acceleration on pavement is now noticeably smoother.
  4. The Mopar wholesalers are not transparent about what is in stock, and not good at responding to emails and calls. I wanted this fixed before taking our airstream out for some backwoods camping, and was pretty frustrated that I could not get an idea of what actual shipping times are. The official Mopar site was transparent about delivery times running into the first or second week of November for orders made last week / this week. The other Mopar reseller sites are all unclear on whether something is actually in stock at their warehouse and have disclaimer language on their shipping time estimates around whether they need to order it from elsewhere. So, instead of saying "out of stock" on items that are out of stock, those sites just omit the "in stock." Buyer beware if you pay for expedited shipping and then end up waiting til mid November anyways while they get it in stock.
  5. The dealership is much more expensive but does seem to offer better warranties on parts. I have a love/hate relationship with Dick's Country Chrysler Jeep Dodge. Their service department front desk staff are always good and they covered an emissions issue that came up before the extended emissions warranty and that they probably did not have to. On the flip side, they told me I needed a new front diff when I'd actually just damaged an inner CV joint seal, and now I've experienced the expense of buying from their parts department. I spent nearly twice as much a would have with the official Mopar site or other Mopar resellers. Worth it for the peace of mind, in this case, but annoying. I know, I know; this is how capitalism works. They had the parts in stock, the parts department staff were friendly and efficient, and I was willing to pay the price. But still, twice the price...

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Discussion Starter · #4 ·
Pulled the old switch apart. Not much on the board that is easily serviceable. If you suspect a dead switch you might check that one capacitor (the one here held 12v fine), and on this board I do see some odd discoloration on the first component connected to the positive power pin. Switch can be reassembled if you are careful in dissassembly, which I was not 😂.
Circuit component Electronic component Electronic engineering Passive circuit component Hardware programmer
 
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