Troubleshooting a Wiring Harness Tripping Warning Lights on a 2019 Toyota Prius
Updated 02/04/2025 | Published 02/02/2025
Question:
Hello, I just installed the trailer harness for the 2019 Prius. I had installed it according to instructions, but when I turned my Prius back on, it was flashing in the displays that the anti-lock brake system, collision detection system, and power braking system are malfunctioning. I’m not sure what happened, maybe I blew a fuse or a relay? Do you know what may have happened and how to fix it? Thank you
asked by: Katrina T
Expert Reply:
Hey Katrina! Did you disconnect the battery when you installed the Curt T-Connector Vehicle Wiring Harness item # C69KR. It definitely sounds like some fuses got fried. I recommend looking at the key above your fuse panel, finding the location of those functions, and checking to see if those fuses are intact. If they are then disconnect your battery, wait a minute, then reinstall it.
If that doesn't solve the problem, I recommend checking your ground. It needs to be securely attached to a completely bare spot of metal. You'll want to grind off any paint or coating at this location.
If these steps don't solve your issue then message me below and we'll find another solution or get you set up with a new harness.
Product Page this Question was Asked From
Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- Vehicle End Connector
- Converter
- No Tow Package
- 4 Flat
- Plug and Lead
- Plug-In
- Hidden
- CURT
more information >
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Katrina T.
2/4/2025
Hi Jerred, Thank you for your reply. The issue actually resolved itself as I drove my car around the next day. I was watching the instructional video that Etrailer provides for the installation and it actually did not tell you to disconnect the battery before beginning the process. In case you might want to edit the video. Thanks again.