RTH: Problem with factory GL320 7-pin plug, no brake signal

Jul 10, 2015 | 10:52 PM

Atoyot1031

Thread Starter

Newbie

Joined: Jul 2015

Posts: 10

Likes: 1

GL320

RTH: Problem with factory GL320 7-pin plug, no brake signal

Newbie here!

We just bought a 09 Gl320 for my DW's DD & to tow a new travel trailer. I've been lurking for awhile & already reinforced my hitch. We went to hook up the new TT today with a Anderson WD hitch & Prodigy RF controller.

Long story short, we were not getting a brake light signal out of the 7-pin connector. Turn signal & running lights worked, but no brake signal.

We are 6.5 hours from home in Salt Lake City & fortunately the SLC Mercedes Benz dealer snuck us into their schedule for tomorrow morning.

Anyone run across this? It sounds like it could be a SAM issue.

Thanks in advance!
Nick

Jul 15, 2015 | 02:12 PM

Atoyot1031

Thread Starter

Newbie

Joined: Jul 2015

Posts: 10

Likes: 1

GL320

Just wanted to followup. The dealership was able to clear the SAM and everything began working. There were no fault codes however.

Jul 21, 2015 | 01:28 AM

Kropf

Senior Member

Joined: May 2007

Posts: 260

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From: Hudson Valley, NY

2005 E55 Black, 2007 GL450 Carneol Red

Wondering... I see that you said 'no fault codes', but did your display show "Trailer brake lamp"?

I get that as soon as I touch the brake pedal with the trailer plugged in.
(Turn signals work, and Emergency Flashers work and illuminates the bright filaments, but no brake lights on either of my two trailers (regular incandescent bulbs - not LEDs), although the GL's brake lamps work.)