GMC Repair: DIC Displays Battery Not Charging Intermintently, fluke 87, pile type

Question
I have a 2003 Yukon LT 2WD, 5.3L Flex, Lately I have been experiencing an intermittent DIC display of "Battery Not Charging" when I first start the vehicle.  The message is only momentary (do not get the chance to acknowledge).  The alternator is putting out a steady 13.65 volts.  The battery is brand new; less than two months old/tested checked ok).  Also one additional item noticed is that the Retained Accessory Power (RAP) does not immediately power off when you open a door.  It will remain on for up to 20 seconds after a door is opened.  Any suggestions?

Answer
Hi
I would check for DTC's in the PCM. If none, here is the criteria for turning on the BATTERY NOT CHARGING" warning
The IPC illuminates the charge indicator in the message center when the following occurs:

The PCM detects that the generator output is less than 11 volts or greater than 16 volts. The IPC receives a class 2 message from the PCM requesting illumination.
The IPC determines that the system voltage is less than 11 volts or greater than 16 volts. The IPC receives a class 2 message from the body control module (BCM) indicating the system voltage.
The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.
The ignition is on, with the engine off.
I have also run into a reprogram for the IPC to correct some DIC conditions.

Also if avalible put a Fluke 87 meter on pin B11 of the IPC.
Put meter in MIN:MAX. Crank truck. If it falls below 11vdc you battery IS bad. I have experienced this also. They check good but put a load on it and they fail. Have the battery tested using a Carbon Pile type tester. Put a LOAD on it see if it holds up.
The electronic testers used now are good, but they can pass a bad battery.
I hope this helps.
Please, if noty follow post back.
Good Luck
Pawl