2015 Yukon engine will not turn off with start/stop button

[Jeff Kinsey]

This morning the wife tells me her 2015 Yukon will not start. After inspection, I determine her battery is almost dead. I connect a battery charger to the battery and let it slow charge for a few hours. When I tried to start it, all of the dash and internal lights would illuminate, but the Yukon wouldn't attempt to turnover. I disconnected the battery, waited a few minutes and reconnected the battery and the car started just fine.

I took the car for a fairly long drive and returned home. I put it in park, pressed the start/stop button to turn off the car, the dash lights cycled down like it normally does, but the engine did not stop running.

I tried to use the RKE (Remote Keyless Entry) transmitter (key fob) to stop the engine, it didn't work either.

The car ran in the driveway for over an hour while I tried different things to turn off the engine.

I ended up pulling fuse #74 (Engine Control Module Ignition) to get it to stop.

Does anyone have a diagnosis of the problem from my description?

 

[68 Grand]

My guess is this may be your issue:

http://sandyblogs.com/techlink/?s=2015+tahoe+pinched+wire&search=Search

Regardless it should definitely be checked out by a dealer. Not being able to shut the vehicle off is a major hazard.

 

[autopcms]

I guess your car might need higher octane fuel. Sometimes carbon build up on the piston and it gets hot enough to ignite the fuel and that's that is why engine keeps running. If it is not the problem, check with a good technician, you need an expert help.

 

[kiboater]

I guess your car might need higher octane fuel. Sometimes carbon build up on the piston and it gets hot enough to ignite the fuel and that's that is why engine keeps running.

When a gas engine does this it is called dieseling or run-on. It usually only lasts for a few seconds, certainly less than 30 seconds and makes a very different sound. It sounds like this engine keeps running normally until the owner figures out some way to shut it down.

 

[68 Grand]

This isn't an engine related problem. The battery draining and start button failing to work are symptoms of an electrical system problem.

Tahoes, Suburbans, and non-Denali Yukons of either length have the 5.3 liter engine that does not need higher than 87 octane fuel. Additionally, higher octane fuel is not the way to get rid of carbon. The proper way to reduce carbon is to use Top Tier Fuel, as recommended in the owners manual:

http://www.toptiergas.com/retailers/

If you use fuel from non-Top Tier stations, it will not have the engine cleaning additives regardless of which octane you choose. At Top Tier stations, it will.