Yukon "Service Battery Charging System"

[Ebonez]

So, My 2009 Yukon Denali throws the "service battery charging system" message on a daily basis. The little red battery light comes on as well and stays on for varying times. The message seems to only come on while the truck is idling or moving at slow speeds (like when I drive down my muddy driveway or stopped at a light). The battery light may be displayed anywhere between 10 seconds to 30 minutes. Performance of the truck doesn't seem to be hurt in any way however the voltage gauge doesn't stay super consistent while driving. I had the old battery checked and replaced shortly after I bought the truck a couple of months back since it had trouble starting. Other daily symptoms include flickering lights and screens while at idle. Yes, the battery cables are corrosion free and securely attached to the battery itself. 

Anyone else experience or have a solution to this issue?

Thanks!

-Eric

[dtnel78]

Have you checked the output of the alternator as I didn't see that mentioned?

 

Take it to a battery dealer that has a test tool that can test the diode in the alternator while cranking. Most non repair shops but parts stores that have the proper tools can do a test and give you a printout showing any issues with your starting / cranking system. 

 

If you have any further questions send me a private message but also check for any codes as even with soft codes they don't always trigger a check engine light. 

 

IS the low voltage, flickering when you have a/c fans on vs off same as with lights vs no lights and other situations? 

[Ebonez]

I havent checked the alternator itself however the voltage on the gauge cluster seems to be within normal operating ranges while running. But, I suppose I might as well swing by a shop and see what they have to say. 

 

Since I replaced the battery the truck fires up right away so I dont believe it it be a battery issue.

 

The flickering is reduced when the AC is off but it is still present. 

[sefiroxx]

Alternator

Also check the tensioner. If not tight, the belt could be slipping.

[stlucas]

did anyone figure it out