Troubleshooting Curt TriFlex that is no Longer Detecting Trailer

Updated 06/29/2017 | Published 06/28/2017

Question:

2007 Toyota Highlander Hybrid My Curt Triflex has been working for a couple of years. Recently I hooked up, and noticed that it showed just a single dot... trailer not connected. Brakes also dont engage. If I step on the brakes... nothing but the dot, even while moving. After playing around a bit, I noticed that when I first plug the trailer in I get CC for a bit, and then DC for a bit, and then the dot. When I unplug, I get DC for a bit, and then the dot. Its not the trailer. I have another tow vehicle 2016 Highlander with a different controller. When I plug into that, everything is fine. Any ideas where to look? Is it possible the unit is defective? Thanks

asked by: Dirk D

Expert Reply:

Since the Curt TriFlex # C24VV isn't detecting the trailer I would start by checking the 7-way at the rear of your 2007 Toyota Highlander. Make sure it's clean and free of any corrosion. Then test the brake circuit pin in the 5 O'clock position when the manual override lever is triggered using a circuit tester like # 3808.

If you're not getting any power at the 7-way then you'll need to test closer to the controller. Cut the blue wire about 10 inches or so from the controller and test it there. If you're still not getting any power then the controller is bad. If you get power here and nothing at the 7-way then you likely have a damaged wire somewhere in between that you'll need to trace down and repair.

If this doesn't help solve your issue let me know what you've found while testing and we'll keep troubleshooting.

expert reply by: Charles S