At 12.2 and 12.4 volts, the battery is not being charged by the alternator.
Did you test the voltage at the alternator main post when engine is running?
If voltage is between 13.5 to 14.5 volts, you have a bad connection between the alternator and the main fuse box or the main fuse is bad.
If it has similar voltage as the voltage between the battery terminals, the alternator is not charging and possible causes are :
1. Faulty alternator.
2. Alternator is not turning fast enough to provide adequate charge. Revv the engine and chack if the voltage increases.
Check the belt tension.
Check the harmonic balancer on the crank pulley if equipped. If the harmonic balancer is faulty, you would tend to see a wavy movement of the pulley and have belting noises.
The charging is not controlled by the PCM so there is nothing you need to do about it.
Sunday, January 17th, 2010 AT 3:36 AM