Turn signal

2016 GMC SIERRA
31,000 MILES • 5.3L • V8 • 4WD • AUTOMATIC
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ADAMWENDORF
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  • 3 POSTS
When I turn on the left turn signal it flashes four times then says fault detected and hyper flashes. It is a Denali so it has the LED lights. Checked the connection and it is good.
Apr 8, 2019 at 3:37 PM
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SCGRANTURISMO
  • CERTIFIED EXPERT
  • 4,897 POSTS
Hello,

Is your vehicle's Malfunction Indicator Lamp (MIL) or "check engine" light illuminated? If it is could you pull the Direct Trouble Code (DTC) for me? I have included a link for you below to go through if you are unfamiliar with how to do this.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please get back to us with what you find out and we will go from there.

Thanks,
Alex
2CarPros
Apr 8, 2019 at 8:58 PM
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ADAMWENDORF
  • MEMBER
  • 3 POSTS
No there is not a check engine light on. When I turn the left turn signal on it flashes normal four times then starts flashing fast. The display on the dash says left rear turn signal fault detected. When the turn is complete and the signal goes off and the signal resets the display goes away. It is only the left signal that does it.
Apr 9, 2019 at 3:54 AM
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SCGRANTURISMO
  • CERTIFIED EXPERT
  • 4,897 POSTS
Hello again,

Just a quick observation here, but isn't your vehicle still under warranty?

Thanks,
Alex
2CarPros
Apr 9, 2019 at 8:59 PM
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ADAMWENDORF
  • MEMBER
  • 3 POSTS
No the bumper to bumper warenty ran out in December.
Apr 10, 2019 at 1:45 AM
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SCGRANTURISMO
  • CERTIFIED EXPERT
  • 4,897 POSTS
Hello again,

I have included for you the factory diagnostic troubleshooting guide for your vehicle's turn signals in the diagrams down below. It is quite involved, so please be patient and go through it step by step. It will require you to use a multi-meter so I have included a link for you to go to below if you are unfamiliar with how to use one.

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Please go through these guides and get back to us with what you are able to find out, please.

Thanks,
Alex
2CarPros
Apr 12, 2019 at 8:40 PM