Does my 2020 GLS450 have a brake controller pre-installed?
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GLS450
Does my 2020 GLS450 have a brake controller pre-installed?
I have never used a motorhome. If I want to tow a trailer, do I need to buy a brake controller separately? How to choose the driving mode? Thank you so much for answering my question
Out Of Control!!
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From: unbegrenzt
2017 GLE350 4MATIC
No, no factory installed electric trailer brake controller. Read the W/X166 sections for a lot of good info on this. I haven’t seen it come up too much yet in the V/X167 sections.
Super Member
Joined: Dec 2013
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From: SW Ontario Canada
2020 GLS580, 2023 Corvette Z06
No brake controller pre- installed but if you have the tow package it has the connections for it if you have the correct adapter. The X167 knows when a trailer is plugged in so it automatically selects/deactivates the driving features for towing. Here are a couple of threads on the subject for this model.
https://mbworld.org/forums/gls-class...ake+controller
https://mbworld.org/forums/gle-class...ake+controller
https://mbworld.org/forums/gls-class...ake+controller
https://mbworld.org/forums/gle-class...ake+controller
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A gaggle of MB's
1. If you have Factory Installed Hitch THEN you have trailer pre-wiring connected to the GLS safety systems
2. Frankly - having a Wireless Brake Controller is much easier than Wired Brake Controller
3. You can check with your MB dealer - however "most" MB dealers do not have significant trailer experience - so you might want to find a Tow/Trailer expert in your area
2. Frankly - having a Wireless Brake Controller is much easier than Wired Brake Controller
3. You can check with your MB dealer - however "most" MB dealers do not have significant trailer experience - so you might want to find a Tow/Trailer expert in your area
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From: Houston Texas
2023 AMG GLE63s, 2017 AMG SL63, 2024 Sprinter, 1958 Chevrolet Corvette
mikecheng - I have an '18 GLS450 and had a Tekonsha brand wireless brake control unit installed and it worked perfectly. No wire splicing into the MB. The hand held unit plugs into the cig lighter for power and you can "dial in" the amount of brake force you want. It essentially is an accelerometer that senses you are braking the vehicle and then it sends the signal to brake the trailer accordingly - you can adjust the force or level of braking with the handheld unit. A local tow / trailer place did the install for me. Good Luck.
Last edited by iridium18; Sep 19, 2021 at 09:00 AM. Reason: misspell
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'21 AMG53 wDPP & ARC, 19 GLC300 - Former-03 C240,2 ML BlueTecs,20 GLE450 E-ABC,15 Cayenne D,17 Macan
mikecheng - I have an '18 GLS450 and had a Tekonsha brand wireless brake control unit installed and it worked perfectly. No wire splicing into the MB. The hand held unit plugs into the cig lighter for power and you can "dial in" the amount of brake force you want. It essentially is an accelerometer that senses you are braking the vehicle and then it sends the signal to brake the trailer accordingly - you can adjust the force or level of braking with the handheld unit. A local tow / trailer place did the install for me. Good Luck.
There is no "splicing into" the car to use a wired controller, there's a socket in by the driver's footwell that you just plug into. You just need an adapter that you can make. When I get home I'll edit this post to add an M-B tech bulletin with parts numbers and directions. About $7. I understand that e-Trailer sells one too.
I vote for the Prodigy RF, I have used the P3 and the RF. That RF works better.
But the accelerometer is located on the trailer, not the Hand held unit, which is one reason it works better, especially at low speeds, like refueling.
I strap my hand held unit to the grab handles on the center console, so it's right at hand for manual brake application. You don't have to fumble around for something hidden in front of your knee.
Talking to the Tekonsha engineers, they say the RF is the best performing controller in their lineup.
Last edited by mikapen; Sep 19, 2021 at 06:59 PM. Reason: Add braker controller technical bulletin
Newbie
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GLS450
Wiring for trailer brakes
A couple of points here.
There is no "splicing into" the car to use a wired controller, there's a socket in by the driver's footwell that you just plug into. You just need an adapter that you can make. When I get home I'll edit this post to add an M-B tech bulletin with parts numbers and directions. About $7. I understand that e-Trailer sells one too.
I vote for the Prodigy RF, I have used the P3 and the RF. That RF works better.
But the accelerometer is located on the trailer, not the Hand held unit, which is one reason it works better, especially at low speeds, like refueling.
I strap my hand held unit to the grab handles on the center console, so it's right at hand for manual brake application. You don't have to fumble around for something hidden in front of your knee.
Talking to the Tekonsha engineers, they say the RF is the best performing controller in their lineup.
There is no "splicing into" the car to use a wired controller, there's a socket in by the driver's footwell that you just plug into. You just need an adapter that you can make. When I get home I'll edit this post to add an M-B tech bulletin with parts numbers and directions. About $7. I understand that e-Trailer sells one too.
I vote for the Prodigy RF, I have used the P3 and the RF. That RF works better.
But the accelerometer is located on the trailer, not the Hand held unit, which is one reason it works better, especially at low speeds, like refueling.
I strap my hand held unit to the grab handles on the center console, so it's right at hand for manual brake application. You don't have to fumble around for something hidden in front of your knee.
Talking to the Tekonsha engineers, they say the RF is the best performing controller in their lineup.
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Newbie
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GLS450
Wiring
Thanks all for guiding me to driver comparment plug in.
Most trailer brake controllers (RF or Hard wire) need 30 amps of +12V power via a 10 or 12 gauge copper wire from battery with adaquate circuit breaker protection.
MB supplied 180 watts (15 amps) to terminal 4 of the 7 wire round receptical for trailer pigtail.
How did you wire new 30 amp power to contoller and then to trailer receptical for pigtail ?
Most trailer brake controllers (RF or Hard wire) need 30 amps of +12V power via a 10 or 12 gauge copper wire from battery with adaquate circuit breaker protection.
MB supplied 180 watts (15 amps) to terminal 4 of the 7 wire round receptical for trailer pigtail.
How did you wire new 30 amp power to contoller and then to trailer receptical for pigtail ?
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Super Member
Joined: Dec 2013
Posts: 628
Likes: 176
From: SW Ontario Canada
2020 GLS580, 2023 Corvette Z06
Thanks all for guiding me to driver comparment plug in.
Most trailer brake controllers (RF or Hard wire) need 30 amps of +12V power via a 10 or 12 gauge copper wire from battery with adaquate circuit breaker protection.
MB supplied 180 watts (15 amps) to terminal 4 of the 7 wire round receptical for trailer pigtail.
How did you wire new 30 amp power to contoller and then to trailer receptical for pigtail ?
Most trailer brake controllers (RF or Hard wire) need 30 amps of +12V power via a 10 or 12 gauge copper wire from battery with adaquate circuit breaker protection.
MB supplied 180 watts (15 amps) to terminal 4 of the 7 wire round receptical for trailer pigtail.
How did you wire new 30 amp power to contoller and then to trailer receptical for pigtail ?
Last edited by marchgroupinc; Oct 1, 2021 at 09:27 AM. Reason: new additional info.
