Jeep smart fob

jeep
cherokee

#1

My 2015 Jeep Cherokee Limited (4WD, V6) experienced a hiccup yesterday. Got up early to do my grocery shopping, stopped a 7-Eleven for cigarettes, then drove home. No problem. Left home to pick up something at Rite Aid before going out to eat. Got out of the car, hit the button on the door to lock it, nothing happened. Tried the lock button on the fob, nothing happened. Did my shopping, came back, same issue. Tried to start the car, information screen said Fob not detected. Swell, sounds like the battery died in the fob (which I think may be a little to soon, only having had the car for 2 1/2 years. Used the emergency key in the fob to lock the door and walked home. Searched through the owner’s manual as I recall having seen a section for starting the car with a low/dead battery in the fob, but couldn’t find it (owner’s manual is 750 pages; that doesn’t include the 250 page manual for the radio). Grabbed the spare fob (I live alone and I have never used the spare fob), walked back to the car, spare fob was also tango uniform. Called AAA and just before the tow truck driver arrived I remembered the emergency starting procedure: use the fob to push the start button. Car started, could go back home. Stopped at post office (since I knew I could start the car), hit the door button to lock the car, it worked. Came out the post office, put my hand behind the driver’s side handle to unlock the car, it worked. Got up this morning to go out to breakfast, it worked, both going and coming home.

Checked the information screen, battery is OK. So the questions are: is the battery on the fob I always use dying/dead after only 2 1/2 years (my previous car’s fob worked for almost 10 years before there was an issue)? If it is, why does the spare fob act the same way? Also the tow truck driver told me that the Batteries and Bulb stores can replace the battery in the fob and even do spot soldering if necessary. Anyone know if this is true and reliable? Thank you.


#2

If both key fobs are doing the same thing then it may be dealer programing time.


#3

I’m guessing both fob batteries are near the end of their life. Batteries have shelf lives, and for fobs, that’s probably what determines how long they last, not how often the fob is used. The reason the fob is intermittent may have to do with ambient temperature changes. A battery that won’t have enough power to do the job at one temperature might at another.

I’m not sure why you’d want to use a Batteries and Bulb store to fix your fob. What does Jeep suggest you to do when the fob battery wears out? At any rate, I think the best approach is to somehow secure a fob with a known good battery and see if that fixes the problem. If that doesn’t work you’ll have to get a dealership involved.

You haven’t recently disconnected the vehicle 12 volt battery recently, right?


#4

I was about to tell you about a TSB (Technical Service Bulletin) for 2015 Jeep Cherokees involving what you are describing. The solution is reprogramming the PCM with the latest software, BUT it seems to be just for smaller displacement engine models (can you say, “four bangers?”).

I didn’t see anything for a V-6 sized displacement engine.

Oh, and I’ve been meaning to talk to you about those cigarettes :grimacing: and eating out all the time. :worried:
CSA


#5

Let’s not judge and/or criticize anybody for smoking cigarettes or eating out all the time

Those are their choices to make

Everybody needs to decide for themselves when . . . or if . . . they will change their lifestyle

None of us are perfect, either


#6

Point taken. In fact you are more polite than I am rude, but I wasn’t trying to criticize lifestyles, but rather improve one’s health.

I watched what years of smoking did to my father and well, I probably assumed too much by thinking that all restaurant food is as bad for one’s health as the stuff that’s sold around here.
CSA


#7

Thank you all for the information.

Update: went out this afternoon, still worked fine. I’ll be calling the dealer tomorrow.

Volvo_V70: my best guess is you may be right.

GeorgeSanJose: it may be the batteries as well; that’s the hoped for solution, but VV70’s answer may be more likely. As for Batteries and Bulbs, I was just curious; I wouldn’t go there, because I’d guess they’d need manufacturer’s programming information, which I doubt they would have. I don’t know how I could secure a fob with a known good battery because the fobs are vehicle specific (as least I sure hope so! Otherwise one of my 3 neighbors with Jeep Cherokees could just drive away with mine - mine is more upgraded). And no, the battery hasn’t been disconnected recently unless you consider 4 months to be recent.

common_sense_answer: thanks for checking that; I checked all the recalls for mine and it has received all the necessary updates so far. As for your other answer, I’ve got a pretty thick skin so feel free to have at it.

db4690: thanks for your answer.


#8

Time for a new battery in your smart key, the key is active while the ignition is on so they discharge while you drive. Some manufactures include smart key replacement in the maintenance schedule at 15,000 miles.

The batteries can be replaced by the vehicle owner, the counter clerk at the battery store or dealer can perform this task for you, there is nothing to program.

Your second key may have become out of sync with the vehicle’s rolling code due to the long period of time between use. Starting the vehicle with that key as you did synchronized it with the receiver, no further action needed.


#9

before you go dealer route, try parking your car on the very same spot where you experienced the issue before and checking if fobs work or not

I had such an incident before and it likely was a heavy RF signal from somewhere: the problem would be present only if parked on the same parking lot, around some spot, not in any other place.


#10

Interesting you should mention that, Andriy. I wondered that myself since there is a cell phone tower about a hundred yards away. However, I go to that particular store every 2 or 3 weeks and usually park in the same general location, sometimes in that exact space so I don’t THINK that is what happened although it certainly is a possibility.


#11

UPDATE: I just spoke with the service department at my local dealership. They said the problem was most likely the batteries and both should be changed. I will be doing that tomorrow. By the way, Andriy: they said your idea was possible, but the batteries are probably the issue.


#12

Bummer. Almost every car can be started with no battery in the fob. Usually, holding it up to the start button works or pushing the start button with the dead fob… Early keyless entry cars had a cover that could be removed and a hidden fob key inserted. Ford/Mazda used that method for a while. I liked your update. I would change both too.


#13

That sounds like a “standard answer” that a dealer would say. I’d change the batteries anyway - couldn’t hurt.

RF interference is certainly possible but should have been considered in the design, but it’s a Chrysler product, owned by Fiat, so…

I’s suggest another possible issue… a software problem. Less than robust software locked up, got confused, went Tango Uniform and lost your fob. You reset it when you used the alternate method of starting the car. Complicated system for the simple task of starting a car. Remember that alternative start procedure for the next time this happens.