I accidentally left key in car at the "ON" position for close to 10 hours (left the car at home), so I use the OBD to find out the Control Module voltage is 13.6V, is that kind of low, what's the normal range supposed to be?

Thanks!

 

What do you get when you use a volt meter when the car is not running, and what do you get when the car is at idle? At what RPM? Did you put a load on the battery such as: the lights, and the heater fan?

13.6V is a little low at idle, should be about 14.2V, but if you put a load on the system and it compensates it is not doing too bad. The battery may be able to come back. If the alternator handles the load, try charging the battery to make sure it keeps the charge.

Testing Alternators and Car Batteries

 

12.5 Is fully charged with the ignition off