mbmama

I have keyless go in my 07 GL450, I can no longer lock/unlock door from the driver side and passenger side at the second row, however it works from the front passenger side and the door behind the passenger side. Any quick fix without taking it to the dealer?

Fourdiesel

battery getting weak in the key? Try to figure out how to take it apart and replace the battery. See if that fixes the problem.

mbmama

If battery was weak then it wouldn't work at all. I don't see a problem from front passenger and rear passenger door, it just doesn't work from driver side and passenger door from behind the driver seat. I even used a second set of key and problem followed. I suspect that door handle switch which is connected to rear door KG control module is messed up. Ideas?

englebenz

It's the door handle, had the same problem with driver side rear door, had it replaced under warranty at dealership. When i used to have the E500 had the same problem on my driver door, ordered the part from the dealer and replaced the handle myself. Took me 15 minutes to swap the door handle. I'm assuming cant be much harder on a GL.

mbmama

But how come the two door handle can be bad at the same time? Mine doesn't work from driver side either door, passenger side works fine. I still suspect more of sensor issue. Thoughts?

englebenz

there is one keyless receiver for each side of the car that controls both doors, that may have gone bad, may have to replace that unit. on my old car (E500) the receiver was behind the rear door panels, i'm assuming the same for GL. If you have time you can take off the inside panel off the rear door and look for it, it's a small box about 2-4 inches long and wide. Worth a try if you want to avoid the dealership.

mbmama

Found it from an older post on a forum. How keyless go works

How KG functions…
Unlock request:
- With key present, switch on inside of driver’s door is activated
- Door handle switch is connected to the rear door KG control module
- Rear door KG control module communicates request to EIS
- EIS transmits command signal to left rear door KG control module
- Left rear door KG control module uses antenna to send a RF signal to wake up the KG key
- Key within range wakes up
- Key transmits authorization code via RF
- RF signal is received by rear window antenna (connected to right antenna amplifier module)
- Right antenna amplifier module send signal to rear KG module
- Rear KG module sends key data to EIS
- EIS provides KG authorization
- EIS generates an “unlock” command plus a signal to left rear door KG control module to open driver’s door when handle is pulled

Interior Compartment Module (located behind ashtray) antenna confirms that key is inside vehicle.

The KG key includes a chip card function and the LED flashes when key responds to a wake-up request.

The Brake Switch signal is required when starting the engine.

The unlock/lock key buttons use IR (infrared) signal whereas KG uses RF (radio).

SebTardif

I have the opposite problem with a Mercedes Benz GL450 2009. From outside the vehicle I cannot unlock from front driver or front passenger by pressing the button on the handle, but both side on second row I can unlock.

What is common for the first row versus the second row? For example, do we have a dedicated CAM cable for that front row that handle signal from the keyless go antenna of both side (front row)? Where is it?

alx

most likely both your door handles are dead. the pass side one died first, you didnt notice. then the driver side one died and you tried others and found that the pass side doesnt work either.

new door handles are fairly cheap and 30 mins tops to replace.

josefrias15

hi,

i have a 2012 GL450 that doesn´t have KG and the keyfobe just work by IR and when the liftgate is open and i point the keyfobe to the rear parking sensor the keyfobe lock and unlock the car normally, any thoughts on this issue?

rgds