Trailer Not Connected

[LarryIT]

I recently towed my boat and put it in the water at the marina for the season. When I got home, I disconnected the trailer and parked the truck in the garage. Started truck up the next day and got a few different alarms (Rear Park Aid Deactivated Trailer attached, Reverse Brake Assist Not Available, Trailer Left Turn Lamps Fault Check Lamps, Cross Traffic Alert Deactivated Trailer Attached). So something thinks trailer is still attached. Brake controller says that there no trailer attached. I tried pulling the negative battery terminal for 20 minutes, pulling fuses 91 and 42. No change in condition. Other symptoms include fast turn signal flash pace inside the the truck, but normal flash outside. Also no lines on backup camera when backing up. If this is a common problem can someone point me in the correct direction? This is a 2022 F150 Lariat 2.7L 502A with very few options. Thanks

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[powerboatr]

fast signal usually indicate burned out bulb
did you submerge trailer lights while still connected to truck by chance?
if so i would look again at the trailer connector fuses to ensure one is not blown for lights
and look at the rear lights on truck, even though you should see a light fault in IP

just throwing that out there

 

[LarryIT]

fast signal usually indicate burned out bulb
did you submerge trailer lights while still connected to truck by chance?
if so i would look again at the trailer connector fuses to ensure one is not blown for lights
and look at the rear lights on truck, even though you should see a light fault in IP

just throwing that out there

I did submerge the trailer, but all the lights on the truck seem to be working. When I connected back up to the trailer the fast flashing goes away and all the trailer turn lights and running lights work fine. It's like the software is not sensing the disconnect of the trailer. After I posted the question yesterday, I drove to the gas station and when I was pulling into the pump, the "Trailer Disconnected" popped up on the screen and everything is back to normal. I don't know why it chose that moment to finally figure out that the trailer was disconnected.

 

[Aron]

I have occasionally received some of those warning messages the next time I start the truck after I had a trailer connected. However, they've all gone away when I start it the NEXT time (e.g., starting twice after trailer disconnect).

Is it possible that you just didn't give it enough time to fully shut the system down between startups? (The Owners' Manual states that some systems remain on up to 90 minutes after you turn the truck "off.")

If that's not it, then you've surpassed the limits of my ability to help.

 

[powerboatr]

I did submerge the trailer, but all the lights on the truck seem to be working. When I connected back up to the trailer the fast flashing goes away and all the trailer turn lights and running lights work fine. It's like the software is not sensing the disconnect of the trailer. After I posted the question yesterday, I drove to the gas station and when I was pulling into the pump, the "Trailer Disconnected" popped up on the screen and everything is back to normal. I don't know why it chose that moment to finally figure out that the trailer was disconnected.

with trailer all plugged in do all the lights work, including truck..tail, license plate , turn signals , brakes etc?
one other question is if trailer has a back up battery for the brakes if trailer becomes un "attached"
if its week or bad, it will cause all kinds of weird stuff, from trailer disconnected to trailer connected to no lights etc
i missed it, are you using the 4 pin trailer or7 pin trailer umbilical. i assume being a boat trailer it only has 4 wires for trailer connection so battery is moot. and as ALWAYS check the ground between trailer and truck. as in use ground through the plug receptacle, not the ball
and verify ground on trailer frame is soundly connected. grounds are a huge problem causing issue with our trucks

either way it should have reset the system if trailer is unplugged
is your trailer saved in sync? if so delete it and try again after a few cold restarts.
then reload your trailer or leave it out
the system is SMART beyond belief, but it also pulls a "windows" now and then and looses its mind over a little issue
i am at end of my advice without being at trailer and truck

 

[DW2020]

I haven’t had this problem, so not speaking from experience.

One suggestion not mentioned yet would be to have a good look inside the truck-side 7 / 4 pin connector. If there is debris or water in there, it might be creating a path between two of the terminals. I could see that being a possible cause for the truck to detect a connection and behave the way you are experiencing.

 

[LarryIT]

I have occasionally received some of those warning messages the next time I start the truck after I had a trailer connected. However, they've all gone away when I start it the NEXT time (e.g., starting twice after trailer disconnect).

Is it possible that you just didn't give it enough time to fully shut the system down between startups? (The Owners' Manual states that some systems remain on up to 90 minutes after you turn the truck "off.")

If that's not it, then you've surpassed the limits of my ability to help.

I had made several short (5 miles) over a couple day period and it didn't clear, After that I started pulling and checking the fuses.

 

[LarryIT]

with trailer all plugged in do all the lights work, including truck..tail, license plate , turn signals , brakes etc?
one other question is if trailer has a back up battery for the brakes if trailer becomes un "attached"
if its week or bad, it will cause all kinds of weird stuff, from trailer disconnected to trailer connected to no lights etc
i missed it, are you using the 4 pin trailer or7 pin trailer umbilical. i assume being a boat trailer it only has 4 wires for trailer connection so battery is moot. and as ALWAYS check the ground between trailer and truck. as in use ground through the plug receptacle, not the ball
and verify ground on trailer frame is soundly connected. grounds are a huge problem causing issue with our trucks

either way it should have reset the system if trailer is unplugged
is your trailer saved in sync? if so delete it and try again after a few cold restarts.
then reload your trailer or leave it out
the system is SMART beyond belief, but it also pulls a "windows" now and then and looses its mind over a little issue
i am at end of my advice without being at trailer and truck

I will try to delete the boat out of the towing profiles. I'm using a 7 pin to 5 pin adapter plug (5th pin is for disable surge for backing up). I remove the adapter when I disconnect the trailer. Thanks!

 

[LarryIT]

I haven’t had this problem, so not speaking from experience.

One suggestion not mentioned yet would be to have a good look inside the truck-side 7 / 4 pin connector. If there is debris or water in there, it might be creating a path between two of the terminals. I could see that being a possible cause for the truck to detect a connection and behave the way you are experiencing.

I crawled under the truck and took a look and didn't see any moisture in the plugs on the backside when the problem was happening. The bumper didn't get submerged when I put the boat in the water. Also check to see if the connectors were tight.

 

[LarryIT]

I ended up connecting to my 4 pin trailer and and my 5 pin trailer just a little while ago and both trailers connect and disconnect just fine. My only guess of what happened is that when I back the trailer into the water, something shorts or grounds causing a condition that the software thinks is a bulb failure, but even though I unhook the trailer, the software still holds onto that condition and doesn't clear it right away. Thanks for all the responses to my problem! I will post again if I learn something new.

 

[Hank573]

I recently towed my boat and put it in the water at the marina for the season. When I got home, I disconnected the trailer and parked the truck in the garage. Started truck up the next day and got a few different alarms (Rear Park Aid Deactivated Trailer attached, Reverse Brake Assist Not Available, Trailer Left Turn Lamps Fault Check Lamps, Cross Traffic Alert Deactivated Trailer Attached). So something thinks trailer is still attached. Brake controller says that there no trailer attached. I tried pulling the negative battery terminal for 20 minutes, pulling fuses 91 and 42. No change in condition. Other symptoms include fast turn signal flash pace inside the the truck, but normal flash outside. Also no lines on backup camera when backing up. If this is a common problem can someone point me in the correct direction? This is a 2022 F150 Lariat 2.7L 502A with very few options. Thanks

Just to let you know you are not seeing thing...I have the exact problem with exactly the same symptoms right down to the the hyper flash without the trailer connected. Here is where mine is different, I had just installed a new TBC module and activated with Forscan, checked with a friends parked trailer. At no time did I back into the water. Everything was fine...all lights, brakes and trailer setup...next I decided to test it with a 7pin tester made from some spare parts everything was fine again, trailer connected unplugged trailer disconnect...The third check started the problem the test lights I made had loose connection at left side brake/turn sending a fault on the message screen brake light out...hope behind hope I disconnected the 7 pin tester, shut truck off figuring that would reset the warning. No luck. I now have all of the messages that you are seeing in your truck....truck is a 2022 Xlt 2.7L 302A with 52a tow package. ie NO TBC. How long did it take before the system decided to clear the fault...sorry this was so long.....Oh one more thing I did plug the truck back into the original trailer I used to test first time and everything worked fine, but it still would not clear the fault after I disconnected the trailer...thanks again for listening....

 

[LarryIT]

Just to let you know you are not seeing thing...I have the exact problem with exactly the same symptoms right down to the the hyper flash without the trailer connected. Here is where mine is different, I had just installed a new TBC module and activated with Forscan, checked with a friends parked trailer. At no time did I back into the water. Everything was fine...all lights, brakes and trailer setup...next I decided to test it with a 7pin tester made from some spare parts everything was fine again, trailer connected unplugged trailer disconnect...The third check started the problem the test lights I made had loose connection at left side brake/turn sending a fault on the message screen brake light out...hope behind hope I disconnected the 7 pin tester, shut truck off figuring that would reset the warning. No luck. I now have all of the messages that you are seeing in your truck....truck is a 2022 Xlt 2.7L 302A with 52a tow package. ie NO TBC. How long did it take before the system decided to clear the fault...sorry this was so long.....Oh one more thing I did plug the truck back into the original trailer I used to test first time and everything worked fine, but it still would not clear the fault after I disconnected the trailer...thanks again for listening....

It took a couple of days to clear. I had pulled a few fuses and the negative cable from battery in that couple of days. Have no idea what event caused it to clear finally. My guess is that the software doesn't know how to properly recover from a problem.

 

[Hank573]

Thanks for the feed back. I have owned F150’s since 1989 with TBC’s and this is the first one I have had a problem with. Guess the trucks are just getting too smart for their own good. Thanks again

 

[Hank573]

Thanks for the feed back. I have owned F150’s since 1989 with TBC’s and this is the first one I have had a problem with. Guess the trucks are just getting too smart for their own good. Thanks again

LarryIT here is a quick update...I fixed the problem this afternoon...Pulled fuse #42, nothing, went for a long stop and go ride (even got gas, just hoping), nothing, disconnected battery, nothing, repaired and retried my 7pin trailer simulator, nothing. Last resort back to Forscan, in doing the programing the first time I noticed in the TRM config. a line under trailer for transmission it was set to manual and I changed to automatic bad choice...I put it back to manual and it corrected all of the faults.....not sure what or why but it fixed it....Happy motoring..

 

[LarryIT]

Had the truck into the dealer a couple of weeks ago and they replaced the trailer brake controller board and reprogramed. Tried hooking up to 3 different trailers. All trailers disconnect properly and no strange alarms, but all 3 trailers and test plug showed the right trailer brake light (passenger side) not working / outputting. Couldn't find individual fuse for this so I called dealer and they are looking into it.

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