Fred_1858

Hi,

I'm experiencing keyless entry/start issues for 2 months. It didn't happen suddenly, it got worse over time.

What is working :
_ lock/unlock doors, open trunk, panic button (horn) when using keyfob
_ open trunk from dash button
_ open fuel door from dashboard

What is not working (outside the car, doors closed, car locked, keyfob in pocket) :
_ push on the exterior driver door button : door led blinks twice, relay clicks in bcm, sometimes message on DIC (intrusion sensor on) : door doesn't open
_ push on the exterior passenger door button : door led stays on 3s, door doesn't open
_ push on the trunk button : nothing, trunk doesn't open

Inside the car, doors closed, car unlocked :
_ push on driver door button : clicks in the BCM, door doesn't open
_ push on passenger door button : nothing happens
_ push on start or accessory: no fobs detected on DIC
Car will start if putting the keyfob in the glove box slot

What I've done so far :
The car battery was weak so I replaced it, did not solve the problem.
I changed the battery in my 2 keyfobs with 2 fresh batteries, no change.
I checked all fuses and relays in the 2 fuse boxes (relay contacts checked with coil energized or not)
I have replaced the 4 relays in the RCDLR.

For your information, I have studied electronics for 5 years and got some tools : digital multimeter, oscillocope, power supply, hot air station...

I can do some testing, my knowledge of the C6 keyless entry is limited, maybe you can help me troubleshoot my car.

Thanks

Chevy Cust Svc

This is not the Corvette ownership experience we strive for. Our team would like the opportunity to learn more about the keyless entry/start issue on your vehicle and investigate ways we can potentially assist. When you get the chance, please send an email to socialmedia@gm.com. Be sure to include your Username and Forum name in the subject line, then provide additional details about your experience in the body of the email. We look forward to your contact.

Fred_1858

Thank you for your offer, I'll send you an email very soon with all the infos I've got.

Fred_1858

Hi,
I wanted to keep you informed of what happened. I emailed GM at the provided email address. They answered they couldn't do anything for me because I'm outside the US. They gave me another email address for GM europe. Those guys forwarded my request to kwparts, that company seems to subcontract the assistance for GM Europe.
Ultimately, Kwparts told me I couldn't diagnose nor reprogram my car and gave me the name of the nearest authorized dealer in France (no official GM dealers here, only US cars importers of many brands).
I'm not surprised because a car maker's goal is to make money by selling, maintaining and fixing cars, not helping people fixing they cars for free.
For many reasons, I still want to diagnose and fix that problem by myself 😉
I've read some posts here about RCDLR problems, I feel less lonely 😂 I above all learned a lot about how the keyless system works.
Because the 2 doors and the trunk are concerned, I assume the problem is not a button, interior or exterior, a latch, a door module, because they can't have failed all at the same time.
I've found a service bulletin on this forum (PIC5961), here is the interesting part :
Because I hear clicks in the BCM but not in the RCDLR, it could be my problem.
I don't know what transistor they're talking about though, too bad...

I've got a 2007 schematic of door locks system (euro specs - with deadbolt), but the pins going to the RCDLR don't match exactly my car.
There are 3 models of RCDLR : 2005, 2006-2007, 2008-2013.
Could someone send me the 2008-2013 schematic from the service manual, it would be much appreciated.

Just in case, if someone has the RCDLR internal schematic, it would be unexpected 😁

Thanks a lot 😉

Aardwolf

Frustrating problems and yes it's not uncommon with the RCDLR. In other posts it's advised to check the solder joints. Have you done a search in the tech or general section? I remember pictures of the RCDLR being posted. If I were you I would make a new post over in tech or general because more people read there.

Vetteman Jack

Moved to C6 Tech/Performance per OP request.

davidfarmer

there are 3 or 4 "antenna" in your car connected to the RCDLR, in addition to the one in the glove box. I'd try and verify those are connected and working. I believe there is a signal strength test if you have access to a Tech2.

In my race car, I had to go back in reinstall all of the antenna to get the car to work. The glove-box slot alone doesn't give consistent results. I'd try and verify the RCDLR wiring. attached is the schematic that I have

Fred_1858

Thanks to the admin to have moved my thread

I've removed the RCDLR from the car and already replaced the 4 relays, their contacts are directly connected to the 4 antennas.
I've done some reverse engineering and found out 3 antennas are connected to NO contacts (doors and trunk), the backup antenna is connected to NC contacts.
I've shorted the pink & pink/black wires of the trunk antenna and checked for continuity at the RCDLR C2 connector, everything's ok. Same for the outside trunk button.

Thank you for the RCDLR connectors pinout, it seems to match with the one I've got. By the way, GM part number is 25938512, with 433MHz receiver and deadbolt option.
The RCDLR in my car is pristine, solder joints are perfect, checked with a good magnifier and DVM.

By checking again the relays, I just realized the stock Axicom relays have 5V coil (voltage not printed on the relays), I've replaced them with Omron 12v coil relays 🙄
I'm going to order a new set, not sure it will solve the problem, I can't imagine 4 bad relays at the same time, but who knows...

Fred_1858

Hi, I've worked on the RCDLR again and replaced the 4 relays with 5v coil ones. Now the keyless entry works for passenger door, trunk and engine start. One of the relays was bad, coil is OK, resistance is within specs but I don't hear the click when connecting 5V to the coil, and contacts don't change position.
Then I've removed and checked the driver door latch and found out one of the 2 integrated switches is always closed whatever the latch position is. I've replaced the latch by a new one (UA2). I have previously tested the switches in the new latch to confirm the diagnostic.
After the replacement, door still won't open, but window goes down and up briefly.
My guess is, because one latch switch was bad, it prevented the latch motor to stop and the circuit that drives the motor may have blown (motor driven by BCM & RCDLR)
I'm currently designing a probe to compare driver/passenger signals since passenger side works and driver side doesn't.

Relays removed

New ones in place 😉