[dxfalconer71]

When I start the car it shows between 11.7 and 12 volts from the charging system. Once it warms up ( I let it idle for about 10 minutes) suddenly starts charging 13.6 to 14.1 volts. Once it's warm can turn off the car and restart no charging problem, but if you let it cool down goes through the same warm up thing and then starts charging again. I tested the ipdm with the on board test and everything seems fine. Could this be the pcm?

 

[MuranoSL2003]

How many miles?

If you are only seeing 11.7 - 12 volts initially, you may have a bad battery... The battery alone if it's healthy should be around 12.3 - 12.17 volts.

Have both tested. Also make sure the battery terminals are totally free of corrosion and snug, and check the negative battery terminal cable grounds under the battery and at the CVT. Replace the cable if there has been a history of severe battery terminal corrosion.

 

[dxfalconer71]

144k .Checked the battery alone this morning, it is at 12.1 volts in the cold (40 degrees this morning). I didnt see any corrosion to speak of. Voltage drops while the car is running until the car warms up then it starts charging 13.6 to 14.1 volts. Makes no sense to me, I'm used to alternators stopping working when they get too warm not the other way around

 

[MuranoSL2003]

Check the serpentine belt to be sure it's in good condition and not slipping when cold.