I installed a 7 pin harness, but didn't see a warning message. I wonder if your brake controller is somehow causing a constant bias on the brake sensing wire? That is the only point that the sytem interfaces with the vehicle braking. Where did the shop tie the brake controller brake pedal input to on the vehicle? Has anyone tried removing that,tconnection to see if the warnrng goes away?

 

to OP, where did they tap the brake signal? Does it still do this if the brake controller is plugged in (they have a plug on the back). If its internally faulted, it will pull that fault onto the brake circuit as most controllers are designed to backfeed onto the OEM circuit (to turn brake light on when hitting trailer brakes).

 

When I installed the brake controller on my 2nd Gen, I tapped the Brake signal wire coming off the Converter box. That way I avoided touching/splicing into the vehicle wiring altogether.

 

I just thought I'd update my original post for anyone else who may have this problem. I took my car to a second dealership who has diagnosed the problem as possible computer feedback or damage to the car's wiring harness. They unplugged the 7 pin wiring from the hitch installer and I still have the same error codes. The computer has error codes that they never seen along with others related to body control and start/stop technology. They will have my car 1-2 weeks while technical support is available through Toyota. Bottom line is I will always have the dealer install things like this in the future. Lesson learned.

 

etrailer.com has complete video installation of a Prodigy 3 on a 3d Gen (2014) Highlander. It looks pretty straight forward, but I didn't trust myself, so I asked a friend who is a journeyman diesel mechanic. He used the video as a guide and completed a very neat, professional installation. Perhaps the Ltd. versions have some unusual components, but the system works perfectly on my XLE.

 

The controller came with directions. If you follow them the brake controller works as designed. Friends paid over three hundred to mount a hitch and wire the plug in. It doesn't seem intimidating to me. Sure a lot easier than some of the tasks I get involved with.

 

Finally repaired

After two different Toyota dealerships looked at my car, I finally have it repaired. When installing the 7 pin harness, the hitch company had tapped into my wires. The tech had damaged the insulation on 2 of the wires which were arcing causing all types of codes. Codes are now cleared and insulation has been repaired in my car.

 

Glad to hear that is fixed. Hopefully the hitch installer covered the costs of the repairs as they were the ones who caused it.

 

Problem is on the 3rd gen, that converter and its collected wires are in the trunk. You pretty much have to go for the wire coming off the brake switch here.

 

Glad to have found this thread. I have a 2016 HL XLE w/ Tekonsha Primus IQ Trailer Brake Controller that is experiencing similar intermittent "Brake override system failure" - warnings. Warning light disappears after restart. Due to no error codes, TSB or Recalls Dealer is baffled. Brake Controller tapped wires are secured with no visible nicks in adjacent wires. Any additional info or experiences on this issue since February 2016? Thanks!

 

Have a 16 Ltd. Also installed a Tekonosha Prodigy controller.

Didn't want to tap into the Toyota wiring if I could help it. Decided that I could tap into the brake wire at the 3/2 converter. Checked with Tekonosha before I did it and they agreed. They advised the installation of a diode in the wiring to prevent feedback from the controller into the Toyota wiring. You can see it in the attached diagram on the Red wire going from the 3/2 converter to the controller.

Toyota actually install a diode in the wiring harness of their trucks for this purpose.

One season of hauling a 3500 lb. pop up camping trailer and a 3800 lb. GVW utility trailer with no problems, working perfect..

The switch installed in the power to the controller is to turn it off. Had a controller in another truck quit and I attributed it partly to the fact that it was always on. This one has the switch with a indicator LED in the handle to indicate when it is on.

Wire colours don't always follow all the way thru. Used what I had in stock from a previous project and just indicated the deviations on the drawing, a copy of which is kept in the truck at all times.

 

As previously mentioned, the key is the diode whether you tap in at the brake switch or the trailer tail light converter. Shame on Toyota for advertising a 5000 tow package, but in fine print only allowing 1000 pounds with no brakes. They could, for a few dollars, provide an electric brake plug in port with needed diode already in place.

 

It is more money, but the Prodigy wireless controller solves all these issues. No connection to the internal vehicle wiring at all. The actual controller is mounted to the trailer tongue and senses G forces and the normal brake light signals. The "controller" in the vehicle is only used for visual feedback, brake power configuration and emergency brake activation. It plugs into any 12V output and does not technically even need to be powered once the system is configured. I used the regular flat four connector that came with the Etrailer trailer module and made up an adapter for round 7 way. I added a 10 gauge wire back to the battery for 12V power to the round 7 way. Works great.

Paul