Problem with Proximity Sensor for Keyfob

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SteveinSD

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Since my purchase in September 2018, I have set the door locks to automatically lock when I walk away from the car. Up until recently, this has worked reliably, with a "success" rate well over 90%. Now, it's basically a 50/50 proposition, where I am often greeted with the strident sound of multiple beeps. My understanding is that the system thinks I have left the keys in the car, but that obviously isn't the case. I typically just pull the keyfob out and lock it that way. Then, I often times return to try to get into the trunk, and it simply won't unlock with the keyfob in my pocket. I'll have to pull the keyfob out and hold down the trunk button.

It seems to me that there is something going on with the proximity sensor, and I'm wondering if anyone else has experienced this. Thinking it might be related to the keyfob itself, I switched to the other one, and have not noticed any difference, which tells me the problem lies with the car. Before I head down to the dealer, I'm hoping someone else may have had a problem and can shed some light on a potential fix.
 
Maybe the battery in the fob is getting weak. I do not use the walk away lock feature. IMO much easier just to press the little black button on the door handle when you close the door. Or press the inside lock button as you are opining the door to get out.
 
I thought it was the battery as well, which is why I tried the other fob (which has never really been used). I guess they could both be bad? Maybe I'll swap them out to see if it helps.
 
I've had the some frustration trying to understand what makes it go from ~100% performance down to <67%.

What I understand is that the fob detects signals from inside the car, and based on the strength of the signals it reports to the car the ECU decides if the fob is inside or outside. My guess is (if it happening to both fobs) something may be interfering with the signal generated in the car. If there is some kind of clutter, especially metallic, that may be in the car that may be weakening the signal from an antenna then it may confuse the fob and thus generate the error beep.

Or perhaps it could be something as simple as gum wrapper foil in the pocket. To this day it still mystifies me why it gets confused at times.
 
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I have been told that there are TWO sensors in the trunk - one near the latch and the other deeper inside - but BOTH are closer to the driver's side of the vehicle. What I've found is that, if I exit the car from the driver's door and cross closely behind the vehicle from left to right, it will often give me the "multiple beep" warning - the same warning it gives if I lean into the trunk with the fob in my pocket. If the vehicle is locked and I approach the trunk from the right, the trunk will not sense the fob and will not open. If I approach the trunk from the center, the trunk will open and, if I approach from the left, the trunk will open. My trunk is usually empty so it's not about objects interfering with the signal - but the same things happened when my trunk was full of boxes and luggage. I think it's just a quirk of the machine...
 
Kerbe said:
I have been told that there are TWO sensors in the trunk - one near the latch and the other deeper inside - but BOTH are closer to the driver's side of the vehicle. What I've found is that, if I exit the car from the driver's door and cross closely behind the vehicle from left to right, it will often give me the "multiple beep" warning - the same warning it gives if I lean into the trunk with the fob in my pocket. If the vehicle is locked and I approach the trunk from the right, the trunk will not sense the fob and will not open. If I approach the trunk from the center, the trunk will open and, if I approach from the left, the trunk will open. My trunk is usually empty so it's not about objects interfering with the signal - but the same things happened when my trunk was full of boxes and luggage. I think it's just a quirk of the machine...
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Not that it negates anything you mentioned, but just for "clarity" (or nit-picking really), the car elements are signal generating antennas, not sensors. Typically the trunk one and the other rear one (near the window?) are on the center-line, but that's just speculation on my part, based on a diagram on one of Honda's generic tech articles (not specific to the Clarity).
 
Ray B said:
the car elements are signal generating antennas, not sensors.
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Not an engineer, so used the colloquial term for "something that senses". If they are generating a signal what, then, receives the response from the fob? Are there also "signal receiving antennas" in the loop?
 
do you have a cellphone charger plugged in? I had one that would interfere withe TPMS system on our CR-V and would light up the TPSM malfunction light. Removing the charger made the issue go away!
 
Kerbe said:
Not an engineer, so used the colloquial term for "something that senses". If they are generating a signal what, then, receives the response from the fob? Are there also "signal receiving antennas" in the loop?
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What I understand is the fob detects the proximity to the various antennae broadcast by the car, and then sends those strength of signal data to the ECU (via a higher frequency signal - the ECU has a receiver to collect that signal from the fob; it is the same system employed when you press a button on the fob). The ECU decides if the fob is inside or outside of the car. I am guessing a bad/obstructed signal from one or more of those antennae may result in a case where it can't reliably say if the fob is in or out. Just speculating.
 
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Kerbe said:
I have been told that there are TWO sensors in the trunk - one near the latch and the other deeper inside - but BOTH are closer to the driver's side of the vehicle. What I've found is that, if I exit the car from the driver's door and cross closely behind the vehicle from left to right, it will often give me the "multiple beep" warning - the same warning it gives if I lean into the trunk with the fob in my pocket. If the vehicle is locked and I approach the trunk from the right, the trunk will not sense the fob and will not open. If I approach the trunk from the center, the trunk will open and, if I approach from the left, the trunk will open. My trunk is usually empty so it's not about objects interfering with the signal - but the same things happened when my trunk was full of boxes and luggage. I think it's just a quirk of the machine...
Click to expand...

I often get the multiple beeps when "I exit the driver's door and cross closely" in front of the vehicle from left to right.
 
I swapped out the battery, but am still having an issue with the trunk. I'm thinking I should try switching the keyfob to my left front pocket to see if that makes any difference. I have noticed in the past that if I grab something out of the trunk with my right hand and the key in my right pocket, I often times will get the multiple beeps. Seems rather ridiculous that I have to take extra precautions to "trick" the system into thinking the keyfob is outside the car when it is, in actuality, outside the car.
 
SteveinSD said:
Since my purchase in September 2018, I have set the door locks to automatically lock when I walk away from the car. Up until recently, this has worked reliably, with a "success" rate well over 90%. Now, it's basically a 50/50 proposition, where I am often greeted with the strident sound of multiple beeps. My understanding is that the system thinks I have left the keys in the car, but that obviously isn't the case. I typically just pull the keyfob out and lock it that way. Then, I often times return to try to get into the trunk, and it simply won't unlock with the keyfob in my pocket. I'll have to pull the keyfob out and hold down the trunk button.

It seems to me that there is something going on with the proximity sensor, and I'm wondering if anyone else has experienced this. Thinking it might be related to the keyfob itself, I switched to the other one, and have not noticed any difference, which tells me the problem lies with the car. Before I head down to the dealer, I'm hoping someone else may have had a problem and can shed some light on a potential fix.
Click to expand...
If the car thinks you left the fob inside, it will not make any noise at all (no beeps). I use the walk away locks and have a success rate similar to SteveinSD. The car wants you to close all of the doors, hear one beep, walk a few feet away and hear a beep/lock. You will hear a series of beeps if you 1) close all of the doors and stay too close to the car and 2) close all of the doors and then open the trunk.

Sometimes, in my garage, if I know I need to get something out of the trunk, I get out of the car and leave that door open. Then I get whatever out of the trunk and close the trunk, then the door and it works. Other times, I don't care if its locked so I let it go. If I am out and it doesn't lock because I have gotten something out of the trunk, I just reopen one of the doors and close it and it locks while I walk away.

It does get quirky with low temps as is happening now.
 
Candice said:
You will hear a series of beeps if you 1) close all of the doors and stay too close to the car
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Hmmm, like sticking around to plug in the car?

I realize this is of no help but I personally don't use the auto-lock feature. Upon purchase and going through all the menu settings, I thought it sounded like a good idea and activated it but found it to be a PITA at home as I frequently need to go back to the car while parked in the garage, get there and realize I don't have the FOB, walk back in the house,........
 
SteveinSD said:
I swapped out the battery, but am still having an issue with the trunk. I'm thinking I should try switching the keyfob to my left front pocket to see if that makes any difference...
Click to expand...

Steve, did switching pockets help? When I first got the car I found I also had random success with the fob when it was in the same pocket as my phone. Since isolating the fob as the sole pocket occupant, auto-lock has worked 100% for me.
 
I've found that the new battery has made a difference, where it performs the way it did when I first purchased the car. I rarely have the multiple beeps anymore.
 
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