Hi all.
Have a 2010 Aveo 1.6 Auto which seems to run smoothly. Consumption is 9L/100km dropping to 8 on the open road.

Was playing with my ELM327 and it picked up this message of an error?

Any ideas of most likely cause ? Where do I look first without many tools ? Have a voltmeter.

Where is the Heated Oxygen sensor 1, bank 1 ?
Does low voltage mean low or none?

Much obliged