Troubleshooting S.H. and P.L. Codes on Draw-Tite I-Command Brake Controller

Updated 03/05/2018 | Published 03/03/2018

Question:

I have a 5535 draw tite brake controller for my 2012 GMC 1500. when I plug my trailer in, it will flash P.L. then S.H.. when I unplug the trailer the controller will flash c , n.c. and then it will flash P.L. and S.H. what is the P.L. and S.H. error codes mean? as they arent listed in the trouble shooting manual that came with brake controller.

asked by: Matt

Expert Reply:

I took a look at the instructions manual for your Draw-Tite I-Command Trailer Brake Controller # 5535. It looks like the "P.L." error code you are seeing indicates a power interruption while the brake pedal is depressed, and the "S.H." code appears when the brake wire sees a short during idle condition. There seems to be some kind of short or wiring issue with your brake controller.

I recommend starting by testing the controller itself to make sure it isn't bad. To do this, you will need to cut the blue wire several inches from the back of the brake controller. Then, using a circuit tester like # PTW2993, test end of the blue wire. It should only show power when you apply the manual override. If you get power at idle, then the controller itself is the issue and it will likely need to be replaced.

If the brake controller checks out okay, then reconnect the blue wire and make your way back to the trailer connector on your Sierra. Check the connector for any debris or corrosion that may have built up inside the pins, cleaning out as needed. You can then use your circuit tester to test the brake output pin on the connector, which again should only show power when activating the manual override on the controller. If you see power at any other point (or no power at all), then you will just need to trace along the wiring from the back of the 7-Way to the front of the truck for any damaged or exposed areas, fixing when needed.

If you are still unable to resolve the issue, please let me know and we can continue to troubleshoot.

expert reply by: Chris R