Help! Rear Hatch won't open using hidden button

[Colby 05]

The hidden button to open the hatch does not work ;help

2005 coupe...1SB if that matters?

I pulled the switch out and tested it with a meter, it's working.

I have 12 volts on the harness that plugs into the button. When a jumper wire is placed in the terminals of the harness with the fob on the rear of the car, it still does not open the hatch.

I've tried placing the fob around different areas of the rear of the car, it didn't matter.

The hatch opens fine when you press the button on the fob.

I hear a clicking sound from the general area of the drivers side seat when I have the door open and the button is pressed. With the fob well out of range(50 ft away), I can still hear that same clicking noise when the button is pressed.

The battery in the fob has been replaced and both doors sense the fob with no problems.

It was intermittent but now it seems to have quit working for good. My thoughts are the rear antenna or the RCDLR(remote control door lock receiver)...or a bad connection to the antenna. It seems like the receiver is getting the command to open the hatch, but fails to get a response when the fob is queried.
Where is the RCDLR located on a 2005 coupe? Where is the rear antenna located and how can it be accessed? I referenced a schematic for the door lock system, but it doesn't help much if I can't locate the antenna or RCDLR

Any technical expertise is greatly appreciated

 

[twiget]

After reading all the troubleshooting you have done, I would guess that the trouble is probably the antenna. I dont know where it would be though. There is also a service bulitin about the RCDLR not recognizing the key fobs. The bulliten number is "07260A Keyless Access System inop". Your problem does not sound like the same one as what is described in the bulliten, but who knows.

Good luck with your troubleshooting.

Jason

 

[Colby 05]

After reading all the troubleshooting you have done, I would guess that the trouble is probably the antenna. I dont know where it would be though. There is also a service bulitin about the RCDLR not recognizing the key fobs. The bulliten number is "07260A Keyless Access System inop". Your problem does not sound like the same one as what is described in the bulliten, but who knows.

Good luck with your troubleshooting.

Jason

Thanks for the welcome and the input

I did find the rear hatch antenna just now. It's behind the rear carpet panel below the latch assembly. It's just a little black plastic box about 3 inches long...it's not just a piece of wire rod like I thought it might be. I'm going to check with GM about the part numbers and see if I can interchange the antennas to check the functionality of the rear one. That's all I know to try at this point

I'm still curious where the RCDLR is if anybody knows?

 

[twiget]

If I remember my basic electronics theory correctly :gap, the size of an antenna is directly related to the wavelenght of the signal it is designed to recieve. The higher the frequency, the shorter the wavelength, and the shorter the antenna needs to be. Based on the range of our key fob's I'd guess they transmit in the low Ghz range at a very low power, which limits their range, but also requires a small antenna.

Jason

 

[Colby 05]

Antenna has 14.5 ohms resistance...dunno if that's good or bad?

Any other input? :W

 

[twiget]

14.5ohms sounds about right for an antenna. It is basically a lenth of wire, so the resistance should be pretty low.

Can you get to the antennas in the doors? If so, I'd suggest ohming out those antennas and comparing those readings to the one from the rear of the car.

Another thing you could try to make sure the rear antenna is working, is to disconnect the door antennas. Then try pressing the hatch release button on the fob. If the hatch opens, you know everything from the antenna to the RCDLR is good.

The reason for disconnecting the door antennas is to make sure the rear antenna is the only one opperational. That way there is no question about if the signal was picked up by one of the door antennas.

Jason

 

[topless82vette]

when you tried the remote hatch button were the keys in the ignition? Certain things on my 1997 camaro will keep the hatch from opening. Like keys in ignition, car not in park etc etc. My remote thing is a pain as well always has been as a matter of fact and seems to only like unlocking the trunk when you are along side the car. Have you tried programming the alarm system to how you want it? maybe thats why it's acting like it is.

 

[twiget]

when you tried the remote hatch button were the keys in the ignition? Certain things on my 1997 camaro will keep the hatch from opening. Like keys in ignition, car not in park etc etc. My remote thing is a pain as well always has been as a matter of fact and seems to only like unlocking the trunk when you are along side the car. Have you tried programming the alarm system to how you want it? maybe thats why it's acting like it is.

C6's do not have a typical ignition system. The when you get in the car, you press the start button, the car sends out a signal to see if there is a key fob present. If it detects the key fob, then it will start the motor, there is no key hole on the dash for an ignition. There is only one actual key hole in on the car, above the license plate on the rear end. It is supposed to be for emergency situations such as power loss.

There is also a button next to the key hole above the license plate. That is supposed to release the hatch, again assuming the car detects the proper key fob. That is the problem Colby is having. When he presses that button, the car is not releasing the rear hatch.

Makng sure the alarm is programmed correctly is a good idea though.

Jason

 

[68Roadster]

My '06 manuals show the RCDLR just above the center vents, you'll have to remove the center accy trim plate.
Hope you got the heck outta Houston!

 

[Colby 05]

What are the details on programming the alarm? What is there to program?

The key opens the hatch...and sets off the alarm :L
The button on the dash opens the hatch and the fob button opens the hatch.

I put the fob next to the door when I was playing with it the other day...it didn't pop when the door antenna would have sensed it. I think the rear antenna has to sense it in order to work. I pulled the drivers side panels apart and couldn't find the antenna for the door. I might have to pull the trim piece and play with the RCDLR to see if that's the problem.

I can't imagine the antenna going bad if it still has continuity, but I don't know if there are some other electronic components in that antenna box that may affect the signal strength.

I'm actually near Lake Conroe, about an hour from downtown Houston, so I'm safe from the hurricane....I think:W

 

[68Roadster]

Colby,
All the antennas are in the rear compartment. You found the rear deck one, the door ones are located on the left and right, behind the carpeting/trim, just aft of the pillar.
The book states that the antennas are controlled by the RCDLR. It (RCDLR) sends an AC voltage signal and provides a ground to the antenna when the button is pressed or the door handle is grabbed. In turn the antenna sends a low freq broadcast challenge to a key fob in range.
I'm trying to figure out why you can pop the lid using the key fob but the button by the license plate doesn't work. Another quote from the good book - The antennas are controlled by the RCDLR. When an exterior door or rear compartment release switch is pressed the respective antenna sends out a challenge to the transmitter which begins passive entry communications, i.e. having the key fob near and pressing the button should open the lid.
I'd be happy to send you the pages from the book if you think it would help.

Oughta be pretty windy in your neck of the woods, take care.....

 

[Colby 05]

I'd be more than appreciative of any documentation you have to offer to help out! I'll PM you my email address if you wouldn't mind sending me those pages? What book do you have and where can I get it? I haven't searched for a service manual on the vette since I haven't had a need for one yet.

Battening down the hatch, the storm moves in tomorrow. Let the huricane party begin! haha

 

[twiget]

I'd be more than appreciative of any documentation you have to offer to help out! I'll PM you my email address if you wouldn't mind sending me those pages? What book do you have and where can I get it? I haven't searched for a service manual on the vette since I haven't had a need for one yet.

Battening down the hatch, the storm moves in tomorrow. Let the huricane party begin! haha

I'm glad someone with a service manual was able to chime in.

You can get '05 service manuals from Helm Inc. Here is the link: http://www.helminc.com/helm/product...ype=N&mscsid=9AH7JD5E954N9PHW1QLPFX0XL1VGBMV6

Jason

 

[68Roadster]

No problem

I'd be more than appreciative of any documentation you have to offer to help out! I'll PM you my email address if you wouldn't mind sending me those pages? What book do you have and where can I get it? I haven't searched for a service manual on the vette since I haven't had a need for one yet.

Battening down the hatch, the storm moves in tomorrow. Let the huricane party begin! haha

PM me your mailing address.....or e-mail address and I'll get them copied and sent to you....cant scan them and there are alot of pages covering keyless entry.....
The link Jason sent you is correct, thats where I buy my manuals from. They run about 140. bucks but they are the best thing going.

We'll be pre-hurricane partying in Dallas tonite and tropical storm partying tomorrow if that thing makes its way up here. Time to put the back patio furniture in the garage.

Hope you guys are OK, looks like the surf and wind have started on the coast. Be safe!

 

[Colby 05]

5 days...no power - SUCKS! The storm took a few shingles, a few limbs but I still have a house with minimal damage. Ike was no joke, it blew in with the force of a freight train, category 2 when it hit us. The eye was 30 miles down the road...scary stuff.

Thanks for the offer, I might pick up the service manual for good reference since it's been recomended

 

[twiget]

Glad to hear you survived Ike well enough.

The service manuals are definately worth the $$$.

Jason