trivette

My car has always started fine with the main key fob that was supplied. The second one had never been used and was in a drawer. Over the weekend I planned to use the car for a couple of errands and when it wasn't in the usual spot I remembered the 'main' fob was still in the shorts I had worn at Car Craft the following Sunday. Rather than go through the laundry basket (no it hadn't gone through the wash) I just grabbed the second fob and drove off. When I returned I retrieved the original fob and later wanted to back the car out for some detailing. I got a "no fob detected" message.
I was able to start it by inserting the fob into the slot by the steering wheel but that's the only way it will start now using that fob. Does it need to be reprogrammed or something? My car is an early one (#307) built in late August so the fobs are almost a year old-maybe a bad battery? Any suggestions before I bring it to the dealer?

SevenTurns

New battery. Almost impossible for a fob to become un-programmed.

MikeC4C5C6...C7

Very likely needs a new battery, based on my experience with same system on my C6.

Thanks for the reminder to see if my second fob on my C7, now at least 10 months old, still works!

~Stingray

I would guess new battery. But that seems odd that less then a year and it already needs replaced. I have have had a key fob for almost 5 years and never replaced the battery.

Motohead279

I wasn't able to find one of my fobs for months now.

Washing some laundry this weekend I hear this banging coming from the dryer... yup, key was in a pair of shorts pocket and went through the wash. Still works.

trivette

I've had some fobs last 3-4 years as well. Not sure why the big discrepancy. I try to keep them away from other fobs, as that supposedly can drain them(?). The single fob like the C7 lends itself to get forgotten in pockets more than earlier ones that you would likely have other keys attached to and notice that something's missing right away.

WelderGuy

"I try to keep them away from other fobs, as that supposedly can drain them(?)."

If you suspect your fobs are talking to each other, you could always wrap them with some tin foil left over from making your hat.

Motohead279

PUGPROUD

My fob always unlocks doors and starts car but every now and then will not unlock/pop the trunk on my vert ? Don't know why...anyone else experience this ?

trivette

I brought the fob with me today and stopped at Batteries + to have it checked. The battery was definitely dead, and when they replaced it and tested there is a constant 'signal' being sent by the fob. My car was 12 miles away in the garage. The guy said some newer fobs are constantly in this 'seek' mode. (I haven't a clue if that is correct or not.) I'll try it tonight and at least see if it now starts the car. I have an appt. on Saturday at the dealer for my initial oil change and I'll bring both fobs with to see if they have any ideas. (I know the fob battery was probably under warranty but my selling dealer is 25 miles away and I would rather spend the $4.75 for a battery than in gas to go there and back during rush hour).

SevenTurns

Proximity remotes emmit a signal, when you're close enough the door can be unlocked and the vehicle started. Battries should usually last 2+ years unless exposed to extreme heat or cold.

Good idea to keep the remotes away from the car when not being used.

1stTimeforEverything

Nothing like keeping your fob clean.

KenHorse

Not true at all.

The FOBS don't transmit anything unless specifically polled by the vehicle first. And the vehicle doesn't poll them unless a) a door is to be opened b) the hatch is to be opened or c) the Ignition/ACC button is pressed

SevenTurns

Didn't say they emit a constant signal. You're the expert here. My bad.

WelderGuy

It's my understanding that those functions are carried out by a radio frequency device in the fob that doesn't use any power from the battery in the fob. That's why the fob has to be so close to the car to open the doors/hatch or start the engine with the push-button in the car.

KenHorse

Uhhhhh no.....

eboggs_jkvl

Not really. When you do something to the car where it verifies the RKE, the RKE transmits a signal to prove validity. If your RKE battery dies, you can place the RKE in the steering wheel column slot where the car can communicate with the RKE and allow you to start the car (presumably to go get a new RKE battery installed).

Elmer

KenHorse

If that were true, you should be able to remove the battery from the FOB and it should still work when polled, right?

In reality, the FOB does indeed transmit (using the battery) whenever a button on it is pushed or when polled by the vehicle. Also, the FOB's transmitter has a range of 167 feet (this is in the manual, on Page 2-3).

As for the limited range when opening the doors/hatch or starting, that most likely has to do with the FOB being able to receive the signal from the car before replying to the poll, which is deliberately limited by design.

eboggs_jkvl

You can try a new battery to see if the problem goes away. If not, your rinse cycle might have rinsed out the electron flow in your RKE and you make need a new RKE.

Elmer

WelderGuy

The system is designed so you can get into the car even if the battery in the fob is completely dead. When you touch the button on the door, the car sends out a signal to see if the fob is nearby. The radio waves in that signal induce a small current in part of the radio frequency device so that it can transmit a reply (I'm here.) without using any power from the fob battery (It's dead.), and the car door opens.

The radio frequency device is much like the security tags they put on high-dollar merchandise that set off an alarm at the store exit. They have no battery, and they only work for short distances because the signal they put out is very weak.

If the fob battery was needed to open the door, you'd have to get it replaced before you could even get into the car, and that could be an unacceptable inconvenience to most people.