Signal light mysteriously turning on and off

[Josalynn]

So our signal light in the 2020 GMC Sierra goes on and off by itself even without the keys in the truck. Also was curious if there's a way manually control the emergency brake.

[BlancoSilverado]

Turn signal?

 

Yes,  the E-Brake, press the button and it will start to engage. I have tried it doing 15 mph and it acted like iI was slamming the E-Brake on. I do not know how it will act with speed.

[Josalynn]

12 minutes ago, BlancoSilverado said:

Turn signal?

 

Yes,  the E-Brake, press the button and it will start to engage. I have tried it doing 15 mph and it acted like iI was slamming the E-Brake on. I do not know how it will act with speed.

Yes the left turn signal it just kind of does what it wants when it feels like it and we have searched for the e brake button and cannot find it and when I looked in the manual it said it was an automatic emergency brake system 

[blckblt]

2019 Silverado Introduces Electronic Parking Brake | GM Authority (google.com)

 

This is a chevy but I think the GMC would be in the same place.  just a button to press.  no handle or pedal.

[Jimmy3500]

On 12/22/2020 at 11:49 AM, Josalynn said:

Yes the left turn signal it just kind of does what it wants when it feels like it and we have searched for the e brake button and cannot find it and when I looked in the manual it said it was an automatic emergency brake system 

I have a 2021 GMC Sierra and have the exact same issue with the left signal. Did you figure out a why to yours?

[silveradosid]

check the tire pressure, gm trucks will flash the signal if it thinks there is a problem

[Jeff_C]

On 11/13/2024 at 6:54 AM, silveradosid said:

check the tire pressure, gm trucks will flash the signal if it thinks there is a problem

☝☝☝☝this right here.☝☝☝☝

IIRC the side and number of flashes will tell you which tire.