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Today I experienced my first issue with the Volt. Earlier in the day I was out running errands and all was well. I parked it and went inside. About 15 minutes later I needed to run another errand and went out to the car. With keyfob in pocket I pressed the unlock button and the doors unlocked. I pulled the handled and opened the door. Then the alarm started to go off. I pressed the start button thinking that would shut off the alarm. It did not. I attempted a second time with the same result. I then pulled the fob out of my pocket and pressed the unlock button which silenced the alarm. Odd but I really didn't give it much thought.

That is until I went to start the car and I received a message on the dash stating the car could not detect the fob and that I should place it in the spot under the armrest so I could start the car. I followed the instructions and the car started. Thinking everything might be straightened out now that the car had been started I turned it off, put the fob in the cup holder, and attempted to start the car. Received the notification the car could not detect the fob.

Thinking the batter may be weak (odd since I only bought it in June) I grabbed the second fob and put it in my pocket. Went to start the car and everything worked as expected (I left my primary fob in the house). I went about my errands using the secondary fob and had no issues. Came home, parked the car, put it on the charger. About 30 minutes later I grabbed the primary fob and went to try starting the car. All worked as expected (secondary fob was in the house).

I recall having read something about this on the forum so I did a search and found a sticky thread from 2016 discussing this very problem. I didn't read every post but symptoms were similar and it seemed to be a glitch. Of the posts I did read I didn't see any mention of the 2018 model year. Disappointed to see that this may still be an issue in the third year production run of the car.
 

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Sounds like one of your fobs has a dying battery. Replace it and the issue should go away.

Also, if you keep the fob in your pants and its buttons are being pressed by other stuff, you may simply be wearing down the battery.
 

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Yes, step one is to pick whichever fob you want to use on a regular basis and replace the battery in that fob. Forget about when it was replaced last. If that doesn't fix the problem, look for sources of interference. Do you place your cell phone in the slot in the center console near where the fob was (cup holder)? Is your cell phone in a pocket close to the fob (cell phone in back left pocket, fob in front left pocket)? If so, try to put some distance between the fob and cell phone. For example, put the cell phone in your back left pocket and fob in front RIGHT pocket to increase the distance between them.

I had a similar problem some months ago and that last suggestion above solved it permanently for me. I've confirmed that my fob has trouble communicating when close to my cell phone, particularly when the NFC feature on the cell phone is turned on.

Mike
 

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The thing about those batteries (same as on computer boards) is that they are very sensitive to drops in voltages. Anything under 3 volts, replace.
 

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The thing about those batteries (same as on computer boards) is that they are very sensitive to drops in voltages. Anything under 3 volts, replace.
Just to make things more complicated, I've found several "dead" ones that registered over 3v on my digital voltmeter. They show 3v+ but the voltmeter doesn't draw enough current to show you that when any load is put on it, it'll drop to under 3v. I gave up trying to test them with a meter.

Mike
 

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Just to make things more complicated, I've found several "dead" ones that registered over 3v on my digital voltmeter. They show 3v+ but the voltmeter doesn't draw enough current to show you that when any load is put on it, it'll drop to under 3v. I gave up trying to test them with a meter.

Mike
Yesterday for the first time, my Volt displayed "Replace battery in remote" on the DIC. I took the battery out of my fob and checked it with my battery tester. It did check "good", but the needle didn't deflect as far into the good range as a brand new one. Lithium cells can be tricky. As you mentioned, they will often read a solid 3 volts until you put any kind of load on them then it drops to zero.
 

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Discussion Starter #7
Thank you for all the suggestions and possible reasons for the issue. I may end up replacing the battery just to be proactive however, for the time being, I'm going to leave the current one in place so I can do some testing on it. After the incident this fob (and associated battery) has worked fine for the four subsequent times I've driven it. My behavior / placement of the fob hasn't changed.

To provide some additional information wrt to the suggestions:

  • The fob, with two physical keys, is the only thing in my pocket.
  • The BMW fob is on its own separate key ring which remains at home when not in use.
  • My cell phones are kept in my left, breast shirt pocket.
  • I do not have NFC enabled on any of my phones.
  • I never received any warning the fob battery was low. Not that this is conclusive the battery doesn't need replacing.

What I find odd is the alarm sounded. The car had to recognize the fob in my pocket as I used the door handle button to unlock it. If the car didn't recognize the fob is should not have unlocked the doors. Furthermore I was able to turn off the alarm by pushing the unlock button on the fob.

Anyway I'll keep any eye on it. Perhaps it was just one of those weird glitches.
 

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Cleaning the terminals of the remote with a cue tip and rubbing alcohol is also a good thing to do. Even a small bit of corrosion can cause a battery that is lower than "normal" operating voltage to not work intermittently.
 

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On my 2017, I had a similar problem. Took it to the dealer and they replaced the receiver somewhere in the back of the car I think. Don't have the paperwork handy but it took a week or two to get the module sent to the dealers as there has been a run on them. I had to leave both FOB's with the service department so they could program them to the new module. That could easily be the problem. It certainly fixed mine. The dealer can probably read the code.
 

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Discussion Starter #10
On my 2017, I had a similar problem. Took it to the dealer and they replaced the receiver somewhere in the back of the car I think. Don't have the paperwork handy but it took a week or two to get the module sent to the dealers as there has been a run on them. I had to leave both FOB's with the service department so they could program them to the new module. That could easily be the problem. It certainly fixed mine. The dealer can probably read the code.
How long ago did you experience the problem?
 

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What I find odd is the alarm sounded. The car had to recognize the fob in my pocket as I used the door handle button to unlock it. If the car didn't recognize the fob is should not have unlocked the doors. Furthermore I was able to turn off the alarm by pushing the unlock button on the fob.
That sounds like it might have been a rare "race condition" where the signal from the fob was intermittent and it may have cut out just as you pressed the unlock button. In a case like that, it's possible that the signal was present long enough to unlock the doors but not long enough for the security system to acknowledge the signal. You'd think the two would be connected so that there's no way to unlock the door without the security system disengaging as part of the process... but who knows how these things are programmed. It might not be that smart.

I believe in all cases where GM replaces the door lock module, multiple codes are set to indicate that the module needs to be replaced.

Mike
 

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How long ago did you experience the problem?
I will guess it was mid July when it happened and early August when it got repaired. That was just after an intermittent TPS went defective & was replaced in July. That is all the trouble I have had with the Volt, other than an intermittent "Parking Brake" issue which I correct by setting the brake & then releasing. I suspect I don't set the parking brake as often as I probably should.
 

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Discussion Starter #13
I will guess it was mid July when it happened and early August when it got repaired. That was just after an intermittent TPS went defective & was replaced in July. That is all the trouble I have had with the Volt, other than an intermittent "Parking Brake" issue which I correct by setting the brake & then releasing. I suspect I don't set the parking brake as often as I probably should.
Thank you for the information. I haven't had any issues with my TPS which seems like another symptom.
 

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Discussion Starter #14
That sounds like it might have been a rare "race condition" where the signal from the fob was intermittent and it may have cut out just as you pressed the unlock button. In a case like that, it's possible that the signal was present long enough to unlock the doors but not long enough for the security system to acknowledge the signal. You'd think the two would be connected so that there's no way to unlock the door without the security system disengaging as part of the process... but who knows how these things are programmed. It might not be that smart.

I believe in all cases where GM replaces the door lock module, multiple codes are set to indicate that the module needs to be replaced.
I'm guessing the inability to start the vehicle without placing the key in the center console is somehow connected to the alarm activating. The security system, which activated the alarm, may have shut down connectivity to that particular fob. Once the car was driven the system may have reset itself thus re-enabling the fob. Of course just a guess on my part but it sounds plausible.
 
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