2020 chevy 2500 sled deck lights

[bk720]

Hey all,

has anyone mounted a deck on a 2020 chevy 2500 yet? Not sure how true it is but from what i have read, the factory trailer plug in found in the truck box don't work great for the marker lights on the deck. Something about it thinking a trailer is connected and the cameras acting weird?

 

[papajake]

Get a adapter that goes from a 7way to a 4way you don’t need a 7way for your deck most new trucks come with 2 plugs

 

[bk720]

my truck gas both the 7 pin and a 4 pin mounted in the box from factory. But what i have heard is that the draw from the LED marker lights on the deck is not enough to keep the system on the truck working property and it acts up. i will know for sure in a few weeks when i mount it. Maybe i need to wire in a resister.

 

[armascott]

I have a 19 Super Duty I had to run a seperate plug for my deck, the factory wiring in the box was thinking a trailer was attached and was throwing all kinds of faults ( says brake and signal lights out etc ).

 

[getzcold]

I have a 19 Super Duty I had to run a seperate plug for my deck, the factory wiring in the box was thinking a trailer was attached and was throwing all kinds of faults ( says brake and signal lights out etc ).

Same thing with mine

 

[Zrock]

Anyone compared the wiring in the box to the wiring on the bumper plug? Im assuming something is different due to the fact the only thing that would get plugged into the box plug is a 5th wheel or gooseneck. Both being large enough to have brakes

 

[acesup800]

If necessary, pop open the taillight assembly and run a 2-wire from the taillight power. Pretty simple.

 

[iceman5689]

If necessary, pop open the taillight assembly and run a 2-wire from the taillight power. Pretty simple.

What he said, installed my truck boss deck on my duramax the same way. Feed it through the pocket in the back corner of the box for a clean install

 

[Dawizman]

I wired mine to the tail lights on my Ram.

 

[captain extreme]

Yep, I attempted over and over to try to use the plug in in the box, just wouldn't work on my 2020....Ended up spicing into the tail light. Its all digital electronic now and senses trail pick up or something, it picks up my trailer but not the deck for some reason. Attempted both 4 plug and 7 round.

Hey all,

has anyone mounted a deck on a 2020 chevy 2500 yet? Not sure how true it is but from what i have read, the factory trailer plug in found in the truck box don't work great for the marker lights on the deck. Something about it thinking a trailer is connected and the cameras acting weird?

 

[Quicksand]

The truck needs to see a 55mA draw on the circut to detect a trailer/sled deck and turn on the lights, LED lights don't draw enough.

if you want it to work normally just go buy one of these

https://www.curtmfg.com/part/57003

Just puts an extra load in the circut

 

[bk720]

yea that's what I was thinking. I have some resisters at work from a old repair I could use as well. wire them inline to draw more.

 

[bk720]

Tried the adapter and no go. At least I didn’t have to purchase it I guess..

 

[Quicksand]

Tried the adapter and no go. At least I didn’t have to purchase it I guess..

The one from curt? weird, I don't see why it wouldn't work

 

[canuck5]

Hey all,

has anyone mounted a deck on a 2020 chevy 2500 yet? Not sure how true it is but from what i have read, the factory trailer plug in found in the truck box don't work great for the marker lights on the deck. Something about it thinking a trailer is connected and the cameras acting weird?

My 17 Ford 350 does this exactly when trying to plug in the deck. I tried messing around with plug to only steal from one source not the turning lights as well. Still senses that circuit is not complete and lets you know on dash. My only solution is to only run lights when deck is extended sleds on. Deck is an expensive tonneau cover the rest of the time.

 

[bk720]

So I tried the curt adapter plug and it did not work. I then wired a light in serious that had a
1.15 amp draw and it still did not work. Any other ideas? Do the truck have to be running ?

 

[Quicksand]

Here's the bulletin from gm talking about this...the wording is kinda screwy but If yours is a 2020 it looks like the extra load needs to be on the trailer stop/turn signal circuit and not the park lamp circuit as they're controlled differently (in bold) But I still don't see why the curt adapter shouldn't work, it's what it's designed to do... The trailer lights do actually work when plugged into an actual trailer right?

#PIT5747: Diagnostic Tip - Trailer Lighting Complaints With Trailering App RPO U1D - (Jun 3, 2020)

Subject:

Diagnostic Tip - Trailer Lighting Complaints With Trailering App RPO U1D

---

Brand:	Model:	Model Year:	VIN:	Engine:	Transmission:
from	to	from	to
Chevrolet	Silverado 1500 (New Model)	2019	All	All	All	All
Chevrolet	Silverado	2020	All	All	All	All
GMC	Sierra 1500 (New Model)	2019	All	All	All	All
GMC	Sierra	2020	All	All	All	All

 

Involved Region or Country	North America
Additional Options (RPO)	With Trailering App RPO U1D
Condition	Some customers may comment that their trailer lighting does not operate in the manner expected. Diagnosing these concerns can be difficult because the issue could either be related to the truck or the trailer. This PI is to provide some additional diagnostic information for the symptoms below: Trailer lighting is inoperative   Trailer detection is not possible   Trailer lights flash intermittently while the ignition/vehicle is OFF   General Information   Any current body style vehicle without RPO U1D, along with all previous model years, are not equipped with a K68 Trailer Lighting Control Module. These vehicles utilize relays to power the trailer connector and do not have features like trailer detection, trailer theft, circuit diagnostics, or bulb outage detection.   Vehicles with RPO U1D, are equipped with a K68 Trailer Lighting Control Module, which powers the trailer lighting circuits to the trailer connector. This provides additional features like trailer detection, trailer theft and trailer lighting circuit diagnostics, such as, trailer bulb outage detection and over current.   2019 Model Year Vehicles - Equipped with U1D use the K68 Trailer Lighting Control Module to control all trailer lighting through pulse width modulated (PWM) voltage. The trailer park, stop/turn signal lamp control circuits must draw at least 55mA of total current to be detected as a trailer or the Trailer Lighting Control Module will not control the lighting circuits to the trailer.   2020 Model Year Vehicles- Equipped with U1D use the K68 Trailer Lighting Control Module to control trailer lighting through pulse width modulated (PWM) voltage to the stop/turn signal and backup lamps. The park lamps utilize an internal printed circuit board (PCB) relay to control the park lamp circuit. This enables additional output current for the park lights. The trailer stop/turn signal lamp control circuits must draw at least 55mA of total current to be detected as a trailer or the Trailer Lighting Control Module will not control the lighting circuits to the trailer.
Cause	Root cause can very, follow the information in the Correction section below.

CorrectionWhen diagnosing a trailer lighting complaint it is recommended to connect the trailer simulator test tool (shown below), GM P/N EL-52641, to the truck's 7 way connector. The K68 Trailer Lighting Control Module will detect the test tool and enable the trailer lighting outputs. Turn on the ignition and operate all the lights: park, LT/RT turn, stop and reverse. If the lights on the test tool illuminate in correlation with the lights on the vehicle and no DTC's or warning messages are displayed, then the truck is operating as designed and no repairs should be performed to the truck.
Note: When the ignition is turned off, while the trailer simulator test tool is connected, it may be noticed that the trailer lighting LED's on the tester flicker/flash randomly. This is normal and is part of the K68 Trailer Lighting Control Module's trailer detection/trailer theft features.

Some trailers have wiring that is in very poor condition. A fault on the customer's trailer may result in DTCs set against the trailer lighting circuits along with DIC warning messages. In some cases, this may even open the K68 Trailer Lighting Control Module Fuse F74UA or F82UA on the vehicle. Verify the customer's trailer wiring is in good working condition.
If, after using the trailer simulator tester, the truck functions properly, you may follow the diagnostic tips listed below to help diagnose a trailer related issue. Trailer issues are NOT covered under warranty, but this information listed below can be used to help the customer/trailer supplier understand and correct any trailer related issues if they so choose.

• Some trailers utilize a trailer mounted control module to operate some or all of the trailer lights. These trailers may use the B+ circuit from the trailer connector to power the trailer lighting circuits. These trailers may not always be detected by the Trailer Lighting Control Module and may set faults. Possible ways to remedy this:  
  A. Load resistors could be added in parallel to the detectable lighting circuits of the trailer, which will increase current draw. One known source is the Curt brand Trailer Wiring Adaptor P/N 57003, which can be plugged inline with the 7 way trailer connector. This adaptor can be used to simulate additional lighting load, allowing the K68 Trailer Lighting Control Module to detect the trailer, however some circuit diagnostics and bulb outage detection will not be possible. The addition of a load resistor/adaptor will be at the customer's/trailer manufacture's discretion.
   
  B. The customer's trailer will need to be rewired to eliminate the trailer mounted control module and have the circuits wired directly to the trailer lamps. This option would allow for the K68 Trailer Lighting Control Module to properly detect the trailer and provide full system features such as, trailer detection, trailer theft, trailer lighting circuit diagnostics, and trailer bulb outage detection. This repair will be at the customer's/trailer manufacture's discretion.
  
• Some non–DOT approved LED lamps may not draw enough current for the K68 Trailer Lighting Control Module to detect a trailer when connected, and the K68 Trailer Lighting Control Module will not enable the lighting circuits to the trailer. Possible ways to remedy this:  
  A. Change one or more trailer lamps on the detectable circuits to incandescent bulbs/ DOT-approved LED lamps to increase the current draw which will maintain full functionality of the K68 Trailer Lighting Control Module. The addition of incandescent bulbs/ DOT-approved LED lamps will be at the customer's/trailer manufacture's discretion.
   
  B. A load resistor could be added in parallel to the detectable lighting circuits of the trailer, which will increase current draw. One known source is the Curt brand Trailer Wiring Adaptor P/N 57003, which can be plugged inline with the 7 way trailer connector. This adaptor can be used to simulate additional lighting load allowing the K68 Trailer Lighting Control Module to detect the trailer, however some circuit diagnostics and bulb outage detection will not be possible. The addition of a load resistor/adaptor will be at the customer's/trailer manufacture's discretion.
  
• Some aftermarket accessories, such as trailer mounted cameras, are incompatible with PWM voltage and may not function correctly when connected to the trailer lighting circuits of the vehicle. One possible way to remedy this is the lighting control circuits can be wired to control a relay, in which the relay will provide stable voltage to the customer's aftermarket accessory. This repair will be at the customer's/trailer manufacture's discretion  
  
• With the ignition OFF, the K68 Trailer Lighting Control Module will periodically pulse the lighting circuits of the trailer to verify it is still connected. Depending on the configuration of the trailer lights, the trailer lights may periodically flash as part of the trailer detection and/or trailer theft features. These flashes correspond to when the K68 Trailer Lighting Control Module pulses the lighting circuits to ensure the trailer is still connected and is considered normal.

 

Version	1
Modified	06/03/2020 Created

 

[bk720]

well that explains a lot of thing.

I have not tried the lights with the truck running before so maybe I should do this. I did try it with the curt adapter while it was running but no go. The closest that I have achieved is having them light up when I press the break pedal. But no marker lights.

And yes.. my plug is wired correctly.

I pulled a travel trailer all summer and did not have any issues with the lights.

the problem with the resister other then additional lights, is they get so hot that I don't trust them.

GMC / Chevy needs to come out with a update. Pay 100K for a truck, cant even get the sled deck lights working..

 

[Quicksand]

well that explains a lot of thing.

I have not tried the lights with the truck running before so maybe I should do this. I did try it with the curt adapter while it was running but no go. The closest that I have achieved is having them light up when I press the break pedal. But no marker lights.

And yes.. my plug is wired correctly.

I pulled a travel trailer all summer and did not have any issues with the lights.

the problem with the resister other then additional lights, is they get so hot that I don't trust them.

GMC / Chevy needs to come out with a update. Pay 100K for a truck, cant even get the sled deck lights working..

I hear ya, out of all the things that need logic and modules to control I don't think trailer lights should be one of them.

 

[bk720]

No doubt.

I will keep trying things and with any luck i will get it working or someone else on SM will get theirs working and report back.