‘16 Suburban P050D, P0300, P2099, U0401 Codes

[Mb1500]

What’s up guys,

 

Having a random cold start rough idle issue with my ‘16 suburban with the ecotec 5.3. This happens completely randomly, typically when colder temperatures outside but not always. MIL will be triggered but will go away after some driving. Some instances it flashes and then will go off. Sometimes when the light is triggered the ABS and stabilitrack light will be on and the transmission will roughly upshift and downshift. The indicator light will go away and typically the shifting will be fixed by shutting the vehicle off for a period of time and then re-starting everything will be back to normal. 

 

From what hat I have gathered U0401 means that the transmission control is not getting good signal during these times. 

 

In regards to the engine, I have between 5-20 misfires counts on all cylinders except #7 which has 80 and #8 which has over 6,000.

 

Obviously there is a problem with #8, being a non AFM cylinder and being of random occurrence I’m thinking injector or coil pack. Any thoughts?

[tbarn]

Clear all and see what comes back first. I would tackle P050D first. 90% chance it is at least one bad injector. A very few have a bad cyl head casting leaking coolant into cylinders.

[FishinDVM]

I am similar to your problems... I'd love to know what you figured out???

[no12nv]

Have all the same codes on my 2017 5.3. Runs like a donkey. Gonna make a date w local gm for warranty.  Gonna take tb spacer out jus incase. Leaving cai air raid,n borla cat back dual sides in. Ranger afm out for weeks pedal commander still in at sport +1. Trucks rough as hell cold, fuel consumption  terible. Power loss is stupid . Throttle body spacer ?? Well it's in value ??? Pedal commander works killer.. Jus a fyi. My remote start don't work anymore... why ?  Not sure.. all I know is my truck ripped n was never a worry or concern from the get go n now I'm not happy.. I'm miss my lil engine that cud.keep y'all posted on outcome. 

[no12nv]

58 minutes ago, no12nv said:

Have all the same codes on my 2017 5.3. Runs like a donkey. Gonna make a date w local gm for warranty.  Gonna take tb spacer out jus incase. Leaving cai air raid,n borla cat back dual sides in. Ranger afm out for weeks pedal commander still in at sport +1. Trucks rough as hell cold, fuel consumption  terible. Power loss is stupid . Throttle body spacer ?? Well it's in value ??? Pedal commander works killer.. Jus a fyi. My remote start don't work anymore... why ?  Not sure.. all I know is my truck ripped n was never a worry or concern from the get go n now I'm not happy.. I'm miss my lil engine that cud.keep 

I did get an original p0101 code but that has since cleared n the rest have came up. I am gonna try a maf clean while removing the spacer for ****** n giggles. But I don't see it changing anything..