Key Fob detecting only intermittently

trent1331

Hey guys,

I've found a fair bit of info in other threads about the key fob not being detected by the car (at all), but my situation is a bit perplexing..

So my Z (2009) is creeping up on 100k miles and it had a good 5-6 month period where it sat with little driving over last Winter/Spring. Now the key fob isn't detected by the car, (so I use the keyfobgina to start it) until I drive her around for some variable amount of time, usually ~30 minutes/20+ miles. Then the car will detect the key normally for a while, even after parking and turning the car off and back on, then without fail after sitting overnight the fob is no longer being detected.

Anyone have any idea? Electrical issue? I can't imagine the fob antenna is disconnected if it works sometimes (I do still plan to check, just haven't had time to pull the console up)..

Only other context I have is that I recently had the roof and windshield replaced by a reputable body shop after the Z was vandalized, but the start of the issue did not coincide with the timing of the repairs.

SouthArk370Z

My guess is that it's either an antenna problem or corroded/dirty battery contacts in the fob.

The FSM (link in sig) will have info on antennae (at least two on the Z), including trouble-shooting procedures. Use a pencil eraser to clean battery contacts. Also check the fob button contacts for dirt and corrosion.

__________________
Steering Lock Links - Search The370Z Bookmarklet - FSM @ NICOclub
Mankind has progressed past the need for war but we haven't evolved that far. - NachoMahma

trent1331

Much appreciated fellow Arky!

SouthArk370Z

Whoo Pig Sooie!

__________________
Steering Lock Links - Search The370Z Bookmarklet - FSM @ NICOclub
Mankind has progressed past the need for war but we haven't evolved that far. - NachoMahma

DrBacon

Make sure you don't have anything plugged into the obd2 port, for whatever reason that seems to have *some* effect on the fob detection.

The actual antennae that the car uses to let it start (but not to unlock the door, that's a different one) with the fob is in the center console area.

But yeah as suggested I'd just try the simplest method first and check over your fob its self. Do you have a spare fob with the same problems?

SouthArk370Z

That's a good possibility.

Going by what I've read on The Intertubes (ie, take it with a grain of salt), the problem is that some dongles emit radio waves at frequencies that interfere with car<->fob communications.

__________________
Steering Lock Links - Search The370Z Bookmarklet - FSM @ NICOclub
Mankind has progressed past the need for war but we haven't evolved that far. - NachoMahma

trent1331

Yep, both fobs act in the same way. First step was replacing the battery in both just to be sure. Oddly enough I went to mess with the car just a bit ago and the fob was detected from the get-go and I haven't started the car in about 2 weeks. And to be clear, when the car stops detecting the fob, it also won't unlock the car remotely or via the door button with the proximity sensor. Seems to be all or nothing.

edit: I guess it either fixed itself or it'll crop back up tomorrow or next week, hah!

brainrain

Hello,

I have the same problem :

I open this thread: Key Fob don't work

At the beginning I did not understand my problem

Sometimes both fobs doesn't work but when I drive 20 minutes/ 15 km, it's work.

I recently washed my car under the wheels and chassis, since then I had no more problems with fobs (I don't know if it's thanks to that)

But last week, the problem with fobs is back, I stayed to press the button to open the safe for 2 minutes with the key in my pocket. Now it's work but i don't know for how long

BUT, when I unplug the car battery, nothing works. Even these buttons (front driver door switch buttons) :



And I can't unlock gas door. I need to run 15 km or 20 min for the front driver door switch buttons to work. Then afterwards these buttons will still work even if the keys are not recognized.

I think the car must recognize the fobs once for the front driver door switch buttons to work.

Attached Images

Panneau-de-commande-en-Fiber-de-carbone-pour-nissan-370z-z34-LHD-RHD-panneau-de-commande.jpg_q50.jpg (64.5 KB, 105 views)

Lannyl81

Bringing this thread back....
The key fob that I have been using since I got the Z stopped being detected so I checked the battery; it was low, replaced and all was good for several weeks. But now it is not detected until I press the lock/unlock buttons...like 10x....and then everything is fine.

I checked the battery and it is still good. The other key fob works first time every time...so appears there is something with this one key fob and not the other.

Any ideas???

Thanks

ChrisDeluca

I’m having the same problem you described. Any solution that you can recommend?

BoilardZ

I had many of the symptoms described here. I replaced the batteries in both fobs, and the problems persisted with both fobs. I checked everything--antennas, wiring, lock mechanisms, etc. Finally, I bought another set of batteries for the fobs, and the problems all disappeared. That was about 8 months ago, and it's still fine.
The moral to this story is: even "new" batteries can be bad. I had even measured the voltage on them, and they were right at 3 V. But there was evidently something wrong with them. Maybe they were defective; maybe they were "stale", who knows. Anyway, batteries are cheap compared to the other fixes, so I'd really encourage you to buy fresh batteries from a reputable dealer (Batteries and Bulbs maybe?), even if you recently already changed your batteries.

ChrisDeluca

I have done exactly that (try new new batteries) - previously they were new batteries - but they were not "brand name" so as you say, maybe they were crap to start.

With a brand new battery today, all is fine - time will tell - a new "crap battery" would be good for about a week or two at most.

Thanks again for the reply.

Chris

brainrain

Hi,

I'm still experiencing the issue with my keys, and I can confirm that it's not a battery-related problem. I even went to test the dealership's batteries, and they're Duracell. When it was working intermittently, both keys would function. So, I can confirm that the issue doesn't stem from the keys themselves but rather from the car. This has been ongoing for several years, and the dealerships in France are unable to repair the 370z. I'm wondering if there might be a malfunctioning electronic module. If so, which one do you think it could be?

Envoyé de mon iPhone en utilisant Tapatalk

ChrisDeluca

With a brand new Duracell battery, my problems have disappeared. So, clearly it isn't a solution in your case, but it did work for me.