2014 Impala 2LT electrical problem

[Rookie#1]

The car is still under warranty but I would like to have a general idea as to the problem before I take it into the dealership. When I first start out in the morning the battery display in the DIC indicates 12.6 Volts. After driving a couple miles the DIC display comes up to 14.7-15 Volts and eventually settles down to 14.2 volts. Yesterday on a 200 mile trip the same thing, started out at 12.6 volts then after a few miles came up to 14.4 volts and settled down at 14.2 volts. All seemed ok at that point and I changed the DIC display to monitor mpg averaging. Later when I stared the car to return home I couldn't bring up the battery or the trip B display on the DIC otherwise the car seemed ok. The next morning I measured the batt voltage with a meter and it read 12.4 volts. Started the engine and the battery charge voltage came up to 15.3 volts. Still no battery or trip B display on the DIC. The 12.4 volt reading kinda led me to think, the day before, part of the trip home the alternator wasn't functioning or is the batt defective. This does't explain why the batt and trip b won't come up on the DIC. Otherwise I think the car is great. Any ideas out there.

[Rookie#1]

Well Folks finally starting to learn how to operate this Impala. Found the battery and B trip were disabled in the DIC. Enabled and now readable. Still am confused on the battery voltage reading. This morning I read the batt voltage with the meter first thing. 12.34 Volts. Started the car and DIC read 15.2 Volts same with the meter. Drove the car for around 30 miles and DIC still displays 15.2 Volts at hiway speed. Drops to 14.7 V at stop lite. Go's back to 15.2 V leaving the stop lite. Don't seem normal to me. Just bought the car last December. Not used to these modern machines.

[Tech II]

Well, a fully charged battery should be 12.65 volts.....

This time of year, the cold will cause it to be slightly lower.....also depends on whether you make short trips or long trips...

Starting a car, normally the voltage on a cold start will be about 14.5, and then slowly drop, as the car reaches normal operating temp, and rpms drop....

This time of year, you probably have a good electrical load on the vehicle....lights, heater fan on high, rear defogger on, etc....... this will cause the PCM to command a higher voltage(the new cars alternators are controlled by the BCM or PCM now).....Supposedly, the BCM/PCM is more sensitive to "loads" on the electrical system....

What you should do is look at your owner's manual, and check for "personalization" of the DIC....it's possible you could have accidentally eliminated that data, and can possibly reprogram it in.....or just drop by a Chevy dealer and ask them to do it for you...after all, it's under warranty....

[Rookie#1]

Thanks for the reply Tech II. I did finally reestablish the batt voltage and Trip B displays on the DIC. Still trying to figure out all the electronic functions on this machine. At present my only confusion is the batt voltage on the DIC and as read by a Digital multimeter is 12.3 V. first thing in the morning. When I start the car the volt reading go's to 15.2 V. I take it on a test drive (approx. 30 miles) with heater, radio, everything I can think of turned off. The DIC display remains on a charge voltage of 15.2 V. This just doesn't seem normal to me based on my experience with cars in the past. Phone call to dealership service dept (25 miles away) suggests there is no problem as long as the car starts. Seems to me kind of a weak response.

[Rookie#1]

OK. Hears the final resolution. After dealership ran a batt analysis two time and came out good. I insisted on a new battery for testing. Now battery functions the way GM manual recommends. On start up DIC volt reading @14.5 volts for @30 sec. Then the DIC reading drops off to @12.6 Volts. Hope this helps someone else.