Hello all, ****EDIT the fix has been found****

I am new to the Corvette world and seem to be experiencing a seemingly common "Key Fob Not Detected" error on my 05 C6 Ls2. Any and all help would be greatly appreciated!

I have been reading threads non stop, but I am hoping to get a jumping off point based on some of my cars symptoms.

Cliff Notes:
Key Fob undetected when starting the car (works intermittently)
locks/radio/hatch all detect the key and let you in at all times
Key fob did not pass the test in the glove box
HOWEVER, Car starts when you unplug and re-plug the BCM

I came out to my car after work, and the car would not start. It was saying key fob not detected. However, the key was being detected enough to let me enter the car, work the windows, radio, and open the back hatch.

I replaced both the car battery and the key fob battery and still had the same issue.

So I had the car towed to the dealership to see if they can diagnose it. After 2.5 hours of their corvette tech on the job, they called me and said he got the car to start after using a jump wire on the negative battery terminal. After turning the car on and off multiple times they said it appears to work, but that it didn't make sense and that they didn't find a culprit. They said if the car decides not to start again to bring it back and they can pick up from where they left off.

I picked up the car and later that day took it to my buddy's auto repair shop who was putting tires, and brakes on the car. Of course the car didn't want to start. He tried the key fob in the glove box test and said it didn't detect the fob when he tried resetting it. However, when he unplugged and re-plugged the BCM the car would fire up. Since, it has been starting intermittently, but whenever it does not start if he unplugs the BCM and re-plugs it, the car starts.

I'm not really sure whether I should start with the BCM, new Key Fob, the key fob receiver or somewhere else. I am really hoping to get some insight based on what's going on.

 

Start by pulling the Fobs down to this level, give the a good cleaning, make sure to tweak the battery prongs so they contact both the battery and board correctly,install a new battery, and see if that helps.
Note, pull the board and gasket out at the same time, then once the two are out of the case, then pull the board out of the gasket.

Attachment 48331307




As for the car not seeing the fob in the glove box slot for it, that one has me worried. Hence even with a dead battery, the fob slot antenna should still be picking up the fob.

Here, what you need to do is pull the glove box, and make sure that the antenna for the fob slot, is in the slot for it in the fob slot.

Hence is clipped in here,


And not loose and just sitting on the back wall someplace loose beside in the slot for it instead.


If both cleaning the fobs and installing new batteries, and making sure that the glove box slot antenna is in it correct position does not solve the problem, then you got electrical gremlin problems with the car, and that one is going to be no joy with hours of work as you go through all wiring connectors in the car to spray clean them of any corrosion instead.

 

Thanks a lot Dano, those are some great starting points. The pictures help a lot as well. To clarify more about the key fob not working in the glove department, things do happen when the key goes in the slot. The gauge cluster comes on an radio works etc., but it still doesn't detect the key. My friend tried the hard reset on the key and it would get hung up on No fob detected.

I will try to clean the key. I visited the dealership again today and let the tech know what it has been doing, and that it will most likely be coming back, he suggested new battery cables so I will try that as well since it is a relatively inexpensive.

 

Don't know if I buy the bad battery cable, but could be that the starter solenoid terminal where the battery and alternator cables bolt together is about to crack off instead. Or, could just be a loose negative battery cable where it bolts to the engine block above the starter if the problem is not just a battery about to give up the ghost.

https://www.corvetteforum.com/forums...post1592849217

If this is the case, just the starter solenoid can be replaced on the starter, instead of replacing the entire starter that cost several hundred dollars instead.

The replacement starter solenoid for the starter is a Delco 10503939 for about $25, and goes by Waiglobal #66-161 too.





As for No fob detected when in the slot to reprogram it back in, that is screaming that the fob antenna is not in the slide clip part of the fob slot for it.
Hence the RCDLR has an antenna in it too just above the radio in the dash, and if the signal from the fob slot antenna is not way, way stronger than the signal from the RCDLR antenna itself (Or the other antenna in the car for the fob as well), the RCDLR not going to allow a fob to be programmed into it.

 

Thank you for the advice Dano523! Sorry for the late reply, I have been out of town for the past couple weeks and the dealership has had the car.

*****update***

The RCDLR module turned out to be the main culprit. After we fixed that module the car has been operating as it should. A couple things I did prior (in case anyone else is experiencing the same symptoms and want to avoid over spending) is a new battery, battery harness, key fob. I bought the car used and only had 1 key fob so it seemed like a good investment either way. But it turned out to be the RCDLR the whole time. $330 including the key and the car was back to normal.

 

In the grand scheme of corvette Tax, $330 is not a bad price to have to pay.

But chances are it was just a cold solder joint in the RCDLR that you could have fixed for free in about 30 mins instead.

The center console take about 20 mins to pull and put back in to get to the RCDLR to remove it, and pulling the RCDLR/pulling the board to re-solder the cold solder joints take about 10 min most.

 

Have the car battery checked... I had the same issue. At first it was just the remotes an every so often It would say the key fob was not detected... however it would eventually start... then one day nothing worked!

Long story short, it turned out to be a dead/dying car battery..

Good luck,

SPEED SAFE, NICK

 

Thanks for the reply Nick! First thing I did was replace the car battery, Key Fob battery and then the battery harness. Another characteristic of the "No Key Fob Detected" was temperature related. When the car was left inside the garage bay over night it would start no problem, when the car was left outside (below 40 degrees) it would give the "No Key Fob detected" After also purchasing a new Key Fob all together, it didn't allow you to reprogram the key. It turned out to be the RCDLR module. Since that has been replaced everything has been perfect!

 

I had an issue where my phone charger if next to FOB would stop it from working. Removed phone charger and problem went away. Good luck, russ

 

Does anyone have a part number for a RCDLR module on an 08 Z06? Also is it possible to DIY it? Mine seems to be doing something very similar.

 

25971235

 

Looks like that is listed as 2010-2013. Are you sure it works for an 08?

Do they require a special tool like a Tech II to program or is it just plug and play? Also do you know the location of the actual unit?

Thanks for the help!

 

Good question. Since they all (05-13) work the same exact way I would assume it's the same part. I do believe it will need to be programmed to the car.

 

Can anyone else comment?

 

RCDLR is located above the radio in figure 12.
http://www.corvetteactioncenter.com/...message-9.html

This will pull the center console benzel so you can get to it.



Yes, a new one will need to be programmed into the car to begin with, then the Fobs will need to be programmed into the RCDLR next to allow the car to start.

https://www.corvetteforum.com/forums...-software.html

As for,
Note sure the problem is the RCDLR, but the BCM instead. Hence would put a Tech II on the car to check the fob signal to start with (tech II will be reading the RCDLR on the GM land bus), and if that is good, and the car will not start, then would be suspect of a problem in the BCM or main connector to the BCM from the RCDLR instead.