Troubleshooting "No Trailer Connection" Warning On Tekonsha P3 90195 Brake Controller

Updated 10/28/2024 | Published 10/25/2024

Question:

I have a nissan xterra and I just put in 7 pin plug and brake controller 90195 and it says no trailer connection with the trailer plugged in .. But I have power at the 7 pin plug with or with out brake pedal depressed .. Everything was plug and play .

asked by: Dave

Expert Reply:

Hey Dave, thanks for getting in touch. There are a few things that could be causing the "no trailer connection" warning on your Tekonsha P3 brake controller.

One thing you can do is find a friend with a vehicle that has a functioning 7-way and try plugging your trailer in. If the same problem happens you know it is an issue with the trailer. If everything works fine it would be a problem with your vehicle. Since the wiring harness was plug and play, I do not suspect an issue with the vehicle wiring.

First, check the 7-way plug on your trailer and see if any of the pins are rusty or corroded. Corrosion on the 7-way can make the controller think it is not connected to a trailer, so check that and clean/replace as needed.

Another possible cause is a ground issue on the trailer side. Check the ground on the trailer, and also check the grounds for each brake assembly. Make sure everything is grounded to good clean metal free or any paint or corrosion.

An open circuit on the brake wire can cause the issue you are having. You should only be getting power to the brake pin when the manual override on the controller is used, so that is also something to check.

Give all of this a try and let me know how it goes. I am happy to help you continue to troubleshoot if needed.

expert reply by: Jesse M

7-way diagram
(click to enlarge)

Dave

10/25/2024

The trailer is fine with other vehicles.. could it be that I got a bad controller? I just got everything from you the other day..

Jesse M.

10/28/2024

@Dave Interesting. I do not think you have a bad controller. Earlier you said you had power at the 7 pin plug with or without brake pedal depressed. Are you saying there is power on the 5 o'clock brake controller output pin? If so this would explain the problem and this would point to the OEM vehicle wiring as the cause of the issue. Likely a short on the brake/12v pin.

Dave

10/25/2024

The brake controller says 0 output voltage and 0 output amps