Trailer Disconnected Notificatin

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Feb 20, 2024 | 05:49 AM

IDI Diesel

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Trailer Disconnected Notificatin

Hey Guys, I have a 2018 F30 Lariat, recently the truck is notifying me of "Trailer Left/Right Brake light Issue" or "trailer Disconnected/Connected". It does this without a trailer connected, upon accelerating or slowing down or just cruising. I removed the connector at the bumper, cleaned and applied dielectric grease to the back side and 7pin/4 flat connectors. This didn't help anything or reduce the notifications. I also toggled "No active trailer" in the dashboard with no success. Is there any other places to look for causes of this? I don't see any chaffed wires or corrosion on the pins. Thanks

Feb 20, 2024 | 06:08 AM

99powerstrokedF250

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Joined: Jan 2010

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Since it's doing it without a trailer connected, you've likely got a short somewhere in the wiring harness that runs from the fuse box back to the plug. It may not be obvious either - wires can chafe on each other INSIDE the outer electrical tape/wire loom with no visible damage outside.

I would say get yourself an Ohm meter, tie it to ground and check all pins, then check all pins to each other, just to rule a short out. If it's not there, then you've gotta move further up the line.

Feb 20, 2024 | 06:37 AM

nickshu

Tuned

Joined: Mar 2021

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From: Northern Colorado, USA

Try plugging in the trailer again then disconnecting. Mine has done this if I unplug my trailer under a certain condition (but I have not figured out what the condition is). Reconnecting and disconnecting the trailer again has always fixed it.

Feb 20, 2024 | 06:39 AM

Poncho450

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From: NY/Canada border

Try the plug up nearer the spare tire. That one is famous for all kinds of gremlins. They often need to be popped apart, cleaned and dielectric grease applied. They're known for water intrusion problems. First place I'd check with the age of the truck.
Look at post #6 here: https://www.ford-trucks.com/forums/1...n-message.html

Feb 20, 2024 | 06:49 AM

IDI Diesel

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I'll check that plug at the spare tire. I plug and unplug a trailers a few times a week and there's no rhyme or reason to the notifications. The tricky thing is i can go a few days without a notification, then may days with sporadic notifications. Doesn't make for an easy reconnect/unconnect option.

Feb 20, 2024 | 07:04 AM

Poncho450

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Joined: Oct 2014

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From: NY/Canada border

Quote:

Originally Posted by IDI Diesel

I've had that stupid plug give me trailer notifications as well as messing up power window functions, radio functions and HVAC functions. Crazy. This was on a new 2017 about 6 months into owning it.
Dealer replaced plug under warranty and all problems went away.