Inserting key in ignition - noise

Wow that is weird, wonder if there was some unknown change between the years.

 

Yep definitely have the big electronic booster and no pedal movement during start up. The MT version has A-TRAC instead of CC so maybe that system is why the AT does it.

 

Not sure, both were made in texas.

 

I am fairly certain that only the TRDOR and Pro have the electric brake booster. Both manual and auto.

Its what allows for CRAWL and ATRAC

 

I have a manual OR. I think it only does the brake pedal move and buzz when your foot is on the brake before the key is turned to on.

 

I have a 2021 and with the drivers window down .. I put my key in the ignition and i hear a psss. Sound probably the fuel pump..

 

Maybe something changed between years, my pedal was silent and didn't move.

 

So can confirm there was a slight "buzzing" sound for like 2 secs as soon as the key was inserted, never noticed it before. Brake pedal did not move.

 

I probably had my truck for 2 years before I heard that buzz, it's certainly not noticeable. I'm thinking the brake pedal must be an AT thing as mine made no noise or movement either.

 

The sound when the key is first inserted is a valve in the fuel system opening to equalize tank pressure. The system runs a pressure test on the tank and evap system when the truck sits. This valve releases any stored pressure.
Ned