Match360

2007 RDX 102,000.
Check charging system indicator will blink on randomly,so when I put scanner on to read data it shows the alternator charging from 15 to 22.5 volts while driving, but putting voltmeter on battery only shows normal voltage.Having scanner and meter side by side they are showing different readings?wondering if somehow the pcm is getting false signals as everything works and car drives great,have changed alternator and a complete fuse box/power dist. center and problem went away for about 8 months?
sorry if this is getting to be a long story but how could the pcm be reading such high voltage when it doesn't exist?

Poveiro

I would say that with engine off, measure voltage with a good voltmeter at battery(should be above 11.8, then start the car and measure voltage again, this reading voltage is coming from the alternator to charge the batt, should go up to about 14.2. This would be the good reading indicating the alternator is well. Other wise the voltage regulator is defective. I dont have any more info, but you can find with google.