Reduced Engine Power

[Mike Q]

I have an ‘08 GMC Sierra Denali AWD 6.2

i recently had to put the spare on and a couple of days later the issues started. Coming to a stop light my engine light came on and display read Stabilitrak off, Traction Control off, Service Traction Control, Reduced Engine Power.  When it happens the truck goes into limp mode and minimal power to the drive train. The truck does get a good vibration in and sputters like a fouled plug. I’m wondering if the difference in the size of the spare tire on a AWD vehicle would cause issues in the gear box or transfer case? I’m checking and replacing things to eliminate possible causes...via YouTube....(cheap fixes). 
so far I’ve replaced all four wheels and tires back to factory specs:

(4) 275/55/20 Tires

factory 20” GMC wheels. 
spark plugs 

spark plug wires 

throttle body

code reader says:

C0242-00 

power train control module

C0899-00

control module power circuit

 Those seem to come up when I go into reverse and at slow speeds 10 mph and under usually parking or coming to a stop.

 

 

[riverbanks]

899 is,went below 9volt threshold, check battery,load test,first,then look for compromised connections

[Mike Q]

I’m currently replacing the ground from the battery. I will check all the grounding points and inspect all the wires where the covering has deteriorated and exposed them to heat and rubbing of other surfaces. I did I load test with my scanner and it checked out fine at idle but not moving. 

[Mike Q]

Now it’s throwing a C0561-71

System Disabled Information Stored - Invalid Data

 

service Stabilitrak and service traction control

[Mike GMC]

If the spare is a different diameter, get the tire fixed first.  I'm not talking about wheel size or tire width, just overall tire diameter.  It sounds like it might be seeing the different wheel speed and freaking out the traction control.

[Mike Q]

 

15 minutes ago, Mike GMC said:

If the spare is a different diameter, get the tire fixed first.  I'm not talking about wheel size or tire width, just overall tire diameter.  It sounds like it might be seeing the different wheel speed and freaking out the traction control.

Well I had made a trip from East Texas down to Houston and it started acting up after that. I did replace all the tires with brand new ones and it’s still going into reduced engine power.

[Mike GMC]

Well, my next guess would be a wheel speed sensor.  Do you have any ABS codes?

[Mike Q]

On my code reader under the ABS section it gave me:

C0242-00 power train control module

C0899-00 control module power circuit 

C0561-71 System disabled info stored, invalid serial data received (but is gone now)

 

but from understanding those are just chassis codes.