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Are you getting the acknowledgment on the info display that the trailer has been connected when you connect the trailer? Have you checked the ground connection to the trailer frame for corrosion or looseness? Perhaps the truck has to sense a sufficient electrical load from the trailer in order to acknowledge the trailer connection and activate the trailer lights and back-up assist.
Its definately not the trailer. When I hook it up to my wife's SUV, all the lights work..park, stop turn. Connect it to the truck..notta
Sup guys - Have a 2016 XLT with the 302A package and backup assist. The first time I used my trailer, I set up the backup assist (placing sticker on trailer and calibrating with measurements) Fast forward two years later, when I hook up my trailer, all I get is park light, no stop or turn signals) I thought it was my lights on the trailer but after hooking it up to my wifes SUV , all the lights function as they should. I'm at a loss of what the issue could be. Any helps and advice is greatly appreciated! TIA!
Did you disable auto start/stop by unplugging the connector from the white module under the dash by any chance?
Its definately not the trailer. When I hook it up to my wife's SUV, all the lights work..park, stop turn. Connect it to the truck..notta
Thanks for uploading the pdf files Mike!
Your welcome, they are from a '19 but should be similar and will give you a starting place.
Looking at diagram 2 of 6 I'm guessing your trouble is the Trailer Module. Your running lights are powered from either a relay in the battery fuses or from the trailer module and they work .
The turn/stop are only fed out of the Trailer module and if you look at diagram 3 of 6 the trailer backup asst. light is fed from it too. (illum2ind). I suggest double check those 2 fuses that feed the module. Fuse numbers might be different on your '16 from those on the drawing from the '19.
I've checked all the fuses that are associated with the trailer brakes. All good.
Engine Bay Compartment:
#34 - Trailer Parl Lamps
#35 - Trailer Stop - Turn relay fuse
#36 - Trailer Lamp Module
#87 - Trailer Backup Lamps
Passenger Foot Well Fuse Box - #14 - Brake
One thing I did notice, when I push in the button for the Back Up assist to turn it on, I get no light on the **** indicating it is on. Looked in the manual to se of there was a fuse specifically for that and didn't see anything obvious
Check #49 too I looked online at a '16 manual and that one also relates to the trailer. Just a guess.........
BCM (Body Control Module behind PS kick panel)
Fuse 4 (5A) - TBC (Trailer Brake Control Module)
BJB (Battery Junction Box under hood)
Fuse 34 (25A) - Trailer Tow Park Lamp Relay
Fuse 35 (20A) - Trailer Tow Module and Trailer Tow Left and Right Relay
Fuse 36 (25A) - TRM (Trailer Tow Module)
Fuse 49 (30A) - TBC (Trailer Brake Control Module)
Relay 79 - Trailer Towing Park Lamp Relay
Fuse 87 (10A) - Trailer Tow Reversing Lamp Relay
Some people disable the Auto Stop/Start by unplugging the bottom connector on this module under the dash close to the brake pedal. That also disables the trailer detection which disables trailer brakes and lights. Check to see if this plug got disconnected someway.
BCM (Body Control Module behind PS kick panel)
Fuse 4 (5A) - TBC (Trailer Brake Control Module)
BJB (Battery Junction Box under hood)
Fuse 34 (25A) - Trailer Tow Park Lamp Relay
Fuse 35 (20A) - Trailer Tow Module and Trailer Tow Left and Right Relay
Fuse 36 (25A) - TRM (Trailer Tow Module)
Fuse 49 (30A) - TBC (Trailer Brake Control Module)
Relay 79 - Trailer Towing Park Lamp Relay
Fuse 87 (10A) - Trailer Tow Reversing Lamp Relay
Where the schematics the same between the model years? Just different fuses and connector numbers?
your sure ...there is a brake control on the dash and a module to the left of the brake pedal..
Yes, at least for my 2015, had to switch to the 4-way after brake wiring went completely belly up on a trailer. They worked when it was intermittent and the dash was warning of brake loss (constantly), but upon starting the truck after a fill-up, no brake/turn. Probably would not have noticed if I wasn't so **** about trailer lights working.
