In my stock 2015 tC, I just fixed a short in my trailer hitch wiring. The short was blowing my tail light fuse. When that happened, the right turn signal started to just turn off after about 8-12 clicks.
In diagnosing the short, I replaced a driver's side tail like bulb, the turn signal/dimmer switch.
When I replaced the dimmer switch on the steering column, the TRAC control light came on and now stays on constantly. Now that the short is fixed, the right turn signal still shuts off after about 10 clicks.

Any ideas where to start with either of these issues?

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I would guess there's something wrong with that additional wiring still. If possible remove that completely and see if the issue persists. Really hard to diagnose electrical issues via the web, but I'd start by removing the aftermarket electronics and re-testing.

 

Thank you for the reply. That gives me a direction. I'm not entirely sure how the trailer harness was wired in but I'll def try and remove it entirely. I would think that it being disconnected would be enough but I guess not. Could the short have damaged the relay?

 

I don't know that relays really get 'damaged'. They generally either work or they don't.

Maybe the factory wiring isn't beefy enough to handle the extra load of the trailer electronics or etc, but without knowing what all was done removing it would be a great first step. You might uncover additional issues with the install or bad grounds/contacting wires/etc that could solve the issue as well.

 

Thanks! I will definitely pull that trailer harness and see what happens.

 

So the trailer harness still had a grounded wire and was causing the turn signal issue. The error code for the Trac control light says the brake actuator assembly is the issue. I am having a hard time finding that part online. I don't really know what that is so that probably doesn't help. Lol.

 

If you fixed the ground issue, try an ECU reset to see if the other code clears up (disconnect the battery for 30 min or so). It might take a while for that code to clear up otherwise. That being said I don't really know what that is either lol. What are the codes you're getting?

 

I actually took the scion to a toyota dealership on Saturday to trace the other ground. I just don't have the circuit probes to do it. So I didn't get the exact error code from the car. Resetting the ECU would make sense. Because the traction control light showed up when I disconnected the battery to replace the turn signal/dimmer switch. I put the steering wheel back on and reconnected the battery, started it up and the light was on. I will disconnect the battery and see if that works. Thank you so much!

I did some more googling and found the part on a toyota parts site. New it's just shy of $2000! The dealership quoted me another $500 to install. So that ain't happening. lol. Used parts on ebay are about 100-150 but with 60k miles.

 

I left the battery disconnected for about and hour and a half but there's no change. The traction control light is still on. I guess the part really is bad. I'll have to do some research to see if I have the skill to replace the brake actuator assembly. If I think I can complete the job in a day then I may get a used one off of ebay. But I'll probably live without the trac control for a while. I appreciate your help.

 

I'm imagining it's that box with all the hoses in it that the master cylinder sends al the fluid to, but IDK how that would be related to your grounding issues and stuff. Brakes are something you don't want to put off though. I imagine it would be fairly easy to replace, but then will need a 4-corner fluid flush (might as well with the age of these cars) to purge the system of air. Check to see if there are any seals/o-rings that you could replace for that box as well as you don't want to end up with leaks there.

Traction control could use that box for some reason, but also there are individual ABS sensors on each wheel. Dealerships love to overcharge, I'd get the codes pulled at a local auto shop if you have one nearby and confirm that's actually what's going on before taking on that big project.