PL Error Code on P2 Trailer Brake Controller Installed on a 2014 Ford F-150

Question:

Trying to switch controller into new truck black wire working. Like it should ground white ok. Red and blue hot all the time. PL error light. Brakes on trailer locked

asked by: John H

Expert Reply:

The PL error on the P2, # 90885, indicates that power is being interrupted when the brake pedal is pressed. If you are using the controller on a 2014 Ford F-150 with a factory trailer connector then you should be using wiring harness # 22292. No other harness will work.

If you are using this harness then make sure the wires that go into the plug that plugs into the truck match the picture I have provided.

If you have hardwired in the controller then you likely have the red wire attached to the wrong brake switch wire. You need the wire that only has power when the brake pedal is pressed. If the wire has power at any other time, like with the head lights or turn signals on for example, then it is not the correct wire.

It is also possible that there is a short further back that is feeding power back and causing the problem. There are some tests you can do to determine if this is the issue.

In the truck cab you will need to sever the blue wire several inches from the back of the controller. Then use a circuit tester such as # PTW2993 to test the end of the blue wire coming out of the controller. It should only have power when you apply the manual override. If it shows power at idle, then there is something wrong with the controller and it will need to be replaced.

If it tests fine then reconnect the blue wire. Then move on to the truck side trailer connector. Many times, dirt or corrosion can cause a short in a trailer connector. Make sure the truck and the trailer side connectors are clean and free of corrosion inside and out.

You can test the brake output pin and it should only show power with the manual override. If it shows power any other time then there is a short somewhere between the connector and the brake controller you will need to track down.

If the truck side checks out fine then it could be the wiring to the brake magnets or the magnets themselves. Inspect the power wires to the magnets and look for pinched, frayed, or damaged wires and fix as needed. Make sure the ground wires are attached to clean and corrosion free bare metal surfaces.

You can visually inspect the magnets and if you can see the copper windings coming through the magnets will need to be replaced. To further test the magnets you can follow the help article I have linked. I have also included some help articles on testing and troubleshooting brake controllers for you.