2016 Highlander Remote Starter Problem

First of all, I apologize for the long post, but I wanted to give a full history of this problem. Here goes:

I bought a 2016 Highlander Limited a few months ago (push button start), and noticed one evening that the interior blue ambient LED lights always stayed on. Even with the truck locked and the smart key inside, I checked the garage to be sure I wasn’t seeing things, and sure enough the lights were on. The footlights under the sideview mirrors, however, remained off. Just the blue LED lights stayed on.

I took it to the dealership, and they determined that the ECU was blown and had to be replaced. So they ordered the part, and this fixed the problem. A few days later, I noticed that the same interior blue ambient LED lights were back on! I tested again and realized the same problem had returned, there was no way to turn the lights off.

I took the truck to a different dealership and they saw that an aftermarket remote starter (Fortin FTX-64-2W) was installed incorrectly and was causing some feedback into the ECU, so they wouldn’t look any further.

I then contacted the dealership where the remote starter had been installed, but they could not locate the original installer. So I found a qualified technician, recommended by Fortin, and had him take a look at it. He determined the installation of the remote starter was sloppy, so didn’t want to touch it. Instead, he offered to reinstall the entire unit, which I agreed to. I even got the original dealership to foot the bill! However, even after reinstalling the unit, the blue LED lights remained on 24/7. So after checking back with the remote starter technician, I decided to have the unit disconnected and take the truck back to Toyota for service. I had the remote starter unit replaced under warranty, just in case, but haven’t had it installed back in the truck for now. In the meantime, I noticed my automatic headlights were no longer working. The dash lights would change intensity when it got dark outside, but the exterior lo beams would not go on unless I manually toggled them on.

I took the truck back to the dealership and they determined that the ECU was blown, so they ordered a second one, and managed to replace it under warranty. This fixed the problem with the interior blue ambient LED lights staying on. They also checked on the automatic headlight problem. They changed the switch, but that didn’t help. Then after further investigation, the Toyota technician found that the Auto Lights Off wire connected to the ECU had been cut and routed through the remote starter. So when the remote starter was disconnected, there was no longer any power going to the ECU. He reconnected the wire, and the automatic headlights function correctly once more.

At this point, everything is functional, but the remote starter hasn’t been reconnected. Because of my history of problems, I hesitate to do this. Honestly, I am considering going back to the dealership and trading the truck for a new one. Do you see any reason why this whole thing could have happened? Could the original faulty install have caused the ECU to blow twice? What about installing it again? I doubt very much that Toyota will pass a third ECU under warranty if it blows again, but I can’t figure out why the remote starter could have caused feedback into it. Maybe the remote starter unit was faulty? As you can tell, I don’t know what to do next… Any suggestions?

That is a crazy one, are your sure it was the ECU and not the BCM? This is a very simple install that only hits about 6 wires or so. Did they mention which circuit was getting "back feed". The wires that are used if getting unwanted signals should have kept the vehicle from starting or possibly blowing the ignition fuse. Nor to knock on the second installer but if he missed putting the auto light wire back together he may have missed something else (we all do from time to time). I agree I would be hesitate to install this unit again. If your set on a remote start maybe look at Viper or iDatalink.

Definitely the ECU. My thought is that the original install was faulty, but hard to tell what was wrong, exactly. Toyota didn’t specify which circuit was faulty either. They just said the ECU was blown. Could the auto lights off wire have blown the ECU, or at least the circuit that controls the LED ambient lights? If I do have the remote starter again, it will be a unit replaced under warranty and I’ll have the installer use T harnesses rather than cutting and splicing.

Sounds like the improperly installed R/S blew the first ECU and also the replacement ECU.
The Fortin units are fine if properly installed.

I don't believe leaving the auto light wire off would affect the ECU other than the auto lights not working.