I recently tried to connect my 2025 GLE 450e to my RV trailer brakes using the Teconsha Prodigy RF wireless brake controller. Had no luck getting the controller paired with the remote. Can this system be used with my GLE 450e?

 

@mikapen uses that controller and might be able to assist.

 

Do you have 12 volt power at the controller?

 

Hi, I don't have a Teconsha but I use a Curt Echo Wireless brake controller. They won't start working unless the trailer/rv is hooked up. Once hooked up it starts showing up in the app for pairing and further configuration. I believe your wireless brake controller will work in similar fashion once you have hooked up everything and have the car turned on. Give it a try.

 

I found that my Curt Wireless controller would pair with my smartphone, but completing the setup does require connection with the trailer system. Everyone should have a test plug device like https://www.etrailer.com/Electrical-...URT/C73NR.html that confirms all the vehicle functions are working properly -- $20 well-spent.

 

One other possibility -- the installation instructions that came with my Curt controller advise that some vehicles that come with a factory installed tow option may need to have the 12 volt power to the 7-way connector activated somewhere in the car settings menu. Check your OM to see if this could be your problem.

 

I have a Tekonsha RF controller, and I've used it on four different tow vehicles, of which three were Mercedes ML/GLE.

I've never had a pairing problem but I've seen it on forums.

The solution, in a couple of forums, was to power the trailer from a different tow vehicle - but the common thread seemed to be no 12 volt power to the trailer-mounted unit. You could try that.

I think in most cases it was because they hadn't plugged in their 7 pin trailer wire, so make sure that it's plugged in with ignition on, and that there's power there.

I recommend getting a tester such as this one from Amazon, to verify power. (The Tekonsha doesn't get power from the trailer.)

CURT 58272 7-Pin RV Blade Trailer Wiring Towing Vehicle Socket Tester, Orange https://a.co/d/h5k09oj

Once it's paired, you can adjust the brake settings and boost. But also, once it's paired and set, the controller will control the brakes whether or not the handheld unit is even plugged in.
You won't be able to activate just the trailer brakes, however.

In those regards, I think it's similar to the Curt, but you have to use your phone for the Curt.

I think it's noticeably better than an in-car controller sensor, because it's attached to the trailer. It seems most noticeable at low speeds such as moving into a campsite or gas station.

Tekonsha engineers are readily available by phone, and they're not only knowledgeable, but helpful in human-speak.

Goog luck. Report back.

 

This thread raised my curiosity about the 7-way connector on my '19 G550, which is rated for 7000 lb. towing capacity. The OM lacks any useful information, and the only illustration shows what is apparently a European trailer plug.

In most venues, any trailer with a gross weight (trailer plus cargo) exceeding 3,000 lbs. must be equipped with trailer brakes and a controller that activates them, and many venues also require a breakaway braking system that activates the brakes in the event the trailer decouples from the tow vehicle. Obviously, this requires that the trailer has its own 12 volt battery, even though normally brake power comes from the vehicle.

My 7-way connector has 7 wires entering it, but the ground, +12 volt, and brake controller wires are at best 16 AWG. A single electric brake mechanism pulls 3 to 4 amps, depending on the brake size. A 2-axle 4 brake trailer consequently requires 12 to 16 amps of current, which is at the current capacity limit for 16 AWG. Apparently, this is acceptable inasmuch as braking, and thus current, is intermittent, and the wire doesn't overheat.

When towing, certain driver assist functions -- lane keeping and blind spot monitoring, to name two-- are deactivated. The vehicle determines this by sensing that trailer lights are connected. Without the connection of trailer lights, power to the 7-way connector is inactive. When I plug in a tester such as the one referenced in earlier posts, if it draws sufficient current, the 7-way connector 's12 volt power is activated, which is necessary for the wireless controller to function.

So the conclusion is that the wireless controller likely has to have the trailer system plugged into it for it to be powered and paired with the remote.

 

I think the Blue wire, the brake wire, is 12ga. It's fatter than the other 7-pin wires, for sure.
Technically, it should be on a circuit breaker, but it's fused only. I never changed to a circuit breaker, and I have done some very long downhills (mostly tranny breaking but....) and never had problems (two axles, 4 brake magnets).

Yes, the RF controller needs 12v power to pair. It's possible that newer trailers with LED lights may not draw enough power to activate MB's 12v supply. (The CAN BUS may not "See" the load.)
Which could explain the success others have had by plugging the Tekonsha RF into another tow vehicle that's hot all the time.

 

The Ground, +12 and Brake wires all appear the same diameter on my G550. I built my own tester from a 7-way trailer plug and a handful of LEDs and resistors. When I plugged it in, the tail light and both turn signal LEDs flashed briefly in unison every couple seconds continuously. But activating the vehicle tail lights or turn signals did not activate the tester LEDs. And there was no +12 (and no brake or reverse, since I have no controller installed) LED illumination. The OM says something about 50 mA, and my tail and turn signal LEDs were pulling only about 20 mA all together. I changed out the resistors so that each LED's current is now about 20 mA. Now when I plug it in, the 3 LEDs flash once, and about 2 seconds later the +12 LED lights up. And the tail light and turn signal LEDs activate. There's also a peculiar noise coming from somewhere when this happens -- not a relay clicking -- sounds more like a vacuum actuator(?).

I'm not sure if the Curt tester pulls enough current -- maybe I'll buy one and check it out. Also, etrailer.com has a wealth of information (Q's & A's) about all these trailer controllers. The OP's answer might be somewhere there.

 

The signal you saw every few seconds, was the CAN BUS sending querying signals, looking for a load. Once sees a load, it'll send current. It also does this with the various computers and nodes in the BUS.

Regarding e-trailer, I looked through a lot of those Q&As and every one I looked at (I think) was wrong. That's based on my experience, and information I found on my trailering forums.

I think the basic issue with the Tekonsha RF is that it needs to have a good 12 volt source in order to pair.

 

@blkadr08 (OP) any luck?

 

Quick follow-up on this -- I acquired a Curt 58273 7-way connector tester for $20 on Amazon. It pulls enough tail light current to activate the 12 volt line and verify operation of the tail light circuits (also verifies the brake circuit and reverse light circuit if your vehicle is equipped this way). Valuable test tool, especially for vehicles that have normally inactive trailer connectors.

 

I have been reading towing threads with interest in brake controllers people are using. I don’t like the idea of mounting anything into the dashboard by my feet and have been reading about a few wireless options. Curt Echo wireless at the 7 pin (not sure how secure this would be with the any of our 7 ping plug) and the tekonsha RF controller (Have not 12v plug up front). I also see that Curt has an Echo underdash option. (https://www.curtmfg.com/part/51190). Anyone have any experience with this controllerd