this is a weird one

[dannyvermin]

'23 DCOR, auto, about 20k miles. i came in a little hot at a stop light yesterday and the front end dove as i would expect, then it came up and bounced back down then up again. kind of felt like i had NO shock absorbers, but i happened to look at the tach and the engine was revving up and down. up to 3k, maybe higher, then dropping down to idle and back up. luckily i had been on the brakes hard and avoided hitting the car that had stopped in front of me. i jammed it in neutral and the revs dropped to where i thought it was going to stall so i jabbed the gas pedal. the revs jumped then dropped to normal idle and it was like it never happened.
no idea WTF that was all about. maybe i freaked out the collision avoidance system or something?

 

[Tomahawk Dog]

Sounds like the fuel pump shut off and came back on.
The truck might have thought you were in an accident UNTIL all other sensors showed normal to the computer.
Computers today control everything; hard braking does activate other controls as well. The truck is anticipating impact.

 

[drizzoh]

I've heard of a couple other trucks doing this around 20k also and then never again. Hopefully it's a fluke.