Intermittently slowly shuts off when turning key off and in park

[Katie Lyman]

2014 silverado 1500

Sometimes when I shut my truck off it will slowly shut down. Like I have time to take the key out of the ignition before it will shut itself down. You can hear it almost as if it runs out of gas and dies. Doesnt do it just randomly. 

 

Also I've had a pulsing vibration. Usually up over 35-40+ it will pulse. I've changed front u joint with no difference. Also wheels and tires have been changed since with no difference. Doesnt matter if on the throttle or off it will pulse/shake.

 

Advice? Thanks in advance 

Edited July 11, 2022 by Katie Lyman

[Jsdirt]

A few things will cause a pulsing action at that speed. If you've got one or more brake calipers hanging up and overheating the rotor(s), that will definitely pulse.  You'd really notice it when applying the brakes.  U-joint problems will shake the vehicle-  not a slow pulse. Wheel balance issues can cause this, too.  Anything in the front will be felt in the steering wheel whether a brake or balance issue.

 

As far as the slow shut down, you've got a wiring problem causing that. Lack of a ground, or a short to power could do this, or possibly the switch itself is failing.

[Jsdirt]

I found this interesting problem of running with the key off in a YouTube video. Not what I would have expected causing the issue!  Check it out: 

 

 

 

Edited July 15, 2022 by Jsdirt