In some instances you may be asked to troubleshoot your MPVI2 or Prolink by connecting it to an AA battery to rule out a hardware issue, here's a short how to.

1) You'll need to insert the raw voltage pid into the #1 slot in your table display 

2) Connect the Red Wire on the Pro Link to the Positive terminal of the AA battery

3) Connect the Black Wire on the Pro Link to the Negative terminal of the AA battery

4) Now connect your interface to your vehicle and begin logging

Without the AA battery connected the voltage will likely hover around 1.34-1.37 volts this is perfectly normal.

New AA batteries will put out ~1.5v-1.6v(my new rayovac hit 1.602v), so if your interface is reading this voltage perfectly in the scanner then you likely have an issue somewhere else, whether its a custom pid that is incorrect or your wideband controller hasn't been properly configured.