corvette_maniac

So the key fob which has been working fine, won't unlock the doors. I had to use the key to get in - but then it started just fine. This is an after market fob that's been working fine since I programmed it. As a support engineer, I often her, "it was working fine yesterday." Everything works until it doesn't. Yes .. I changed the battery in the fob.

I have a factory fob and am going to program it later. Anything else I can try?

LCZ06

What year? When mine was messing up it had to do with the car battery. I would check yours out first.

corvette_maniac

It's a 2008. I now get the dreaded "no fobs detected." I disconnected the red top battery.

Vette_DD

Be sure you're not carrying something in the same pocket with the fob that's blocking the signal.

corvette_maniac

I thought about that. Unless someone in my house has erected a high powered transmitter, I'm gonna guess no RF interference.
The battery is only a few months old, it's an Optima red-top.

Also I put the keyfob in the slot behind the glove box to no avail.

oldcanuck

Did you check fob battery and car battery with a volt meter? As an engineer (don't know what a support engineer is) I hope you did.

corvette_maniac

I checked both with a voltmeter.

madsonp

And what did the fob battery read ? A brand new one should read 3.3 V DC

gdmoore01

Plugging the fob into the glove box slot (assuming you did so properly but no detail as to orientation) will eliminate the fob battery as the problem, and leads to some other issue. If you know the auto battery is fully charged and no dead cells (at least 12.6v or higher) then just pulling a battery cable and reconnecting it will reboot all the cars modules and hopefully resolve your problem. Best to start with the easy ones first.

Also, if you have something new plugged into the auto receptacles (phone charger, cables, etc.) disconnect them to see if that eliminates any possible interference.

Let us know (in detail) what steps you are taking and results; Good luck...GD

Vette_DD

Wait and let someone ask you the particulars of how you mounted it there. Someone else has posted here in the recent past about exactly how that fob should be mounted, but I don't know those particulars.

I can say to be sure you don't have anything plugged into the electrical outlet between the seats.

corvette_maniac

The orientation was proper and still didn't work. The battery is 12.4v. The fob battery swap made no difference. It's either a transmit or receive issue. I'll start with transmit: I have a Tek2 clone, might break that out and setup my new key fob. It has to be done anyhow. If it's a recieve issue, it'll be time to break our the service manual.

I was not able to unlock the door, I had to use the key and set the alarm to get in. The car cranked right up. I stopped it, tried again and was not able to unlock or start the car. That's the history.

gdmoore01

OK, still didn't see information that you performed a module reset by disconnecting & reconnecting the battery. If you haven't, try it, as these cars are crazy sensitive to battery power, so a main battery swap with a truly healthy unit (12.4v is not fully charged) may just do the trick. Batteries may not come to a fully charged state due to some internal failure that results a no start condition based on a load fault.

Also, are you hearing any of the normal relay clicking sounds coming from the RCDLR module (located in the upper center dash above the radio) when you enter the car with a fob prior to attempting the auto start function, green light coming on the ignition switch upon entering?

GD

corvette_maniac

I disconnected the battery a few hours ago and haven't gotten back to it yet. That's exactly what I'm hoping for is a module reset to clear the issue.
I was hearing the normal clicking ....and didn't notice the green light though. When I reconnect the battery shortly .... I'll check those things. Hopefully it will be resolved.

SivaSuryaKshatriya

Just as an additional data point, I have the same problem. I replaced the battery on my FOB and while I can unlock the doors, I can't pop the trunk or get the car to recognize that the FOB is in the vehicle. I have to put it in my glovebox which is kind of annoying. I have a brand new battery but it did die once when I forgot to trickle charge my car while it sat for 2 weeks. Following the thread for a fix.

corvette_maniac

Good info.

So I got the battery connected back and there was no change. I had to put the fob in the slot and push start 4 or 5 times and it would start. As soon as I shut it off, I got the message: "NO FOB - OFF OR RUN". I could restart without any problem but once I held down the ACC - -there was no restarting it.

I'm thinking it's the fob. Think it's time to program the new factory fob?

corvette_maniac

Update. Looks like we're good. The reset did indeed fix it. Just after the reset, I tested with a faulty fob. DUH.
With the proper key fob - ALLS GOOD!!!

madsonp

Have your battery load tested (Autozone will do this for free) Chances are if your battery was fully dead, they usually never fully recover. As far as your fob battery, it could be new but has set on the shelf for a while, and it may be bad also, take a multimeter and test the voltage of it, a new one should show 3.3 Volts DC.

Vette_DD

Buy fob batteries somewhere that sells a lot of them, like Walmart.

corvette_maniac

Well the red top was never fully dead. It's been fine since I got it several months ago. I've not heard good things about them and I have 3 other vehicles with them.

gdmoore01

How many fobs do you have? Does the car have the personaliztion functions? If you only have one, then there is no problem with programming fob2 and it will also have the ability to provide personalization settings, but this function will not work for fob3 & fob4. The latter two will perform all necessary auto functions with the exception of personalization.

Just read your update...good to hear. You should probably program another fob as a backup should you misplace the good one.

GD