Troubleshooting Brake Controller Install Brake Light Error Code on Truck Dash

Question:

Installed the P3 brake controller 90195 with 3015-P adapter in my 2004 chevy silverado 3500 dually diesel. Went down the road without trailer attached and the brake dash light on instrument panel started flashing. Any ideas on why?

asked by: Mike

Helpful Expert Reply:

When a brake controller installs with a plug and play adapter like the part # 3015-P the brake controller typically does not cause any issues on the vehicle wiring. The P3 part # 90195 has an on-board diagnostic display that would normally alert you to any issues as well. So while it seems like the controller is at fault since the issue came up right after the brake controller install it would appear to be most likely a coincidence. You can test this though by unplugging the controller to see if the problem goes away.

My theory is that there's a short on the trailer wiring which is causing voltage to backfeed onto the truck's wiriing and cause the issue you are having. I'd get out and check to see if all of the blinkers, brake lights, and stoplights work on the truck and trailer and go from there. Also you should check to see if the third brake light on your 2004 Silverado is still functioning. Your generation of GM truck is known to easily blow the third brake light fuse.

I attached a couple help articles on troubleshooting trailer wiring and brake controllers for you to check out as well.

expert reply by: Jameson C