DTC P0031: Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 1 Sensor 1), DTC P0032: Oxygen (A/F) Sensor Heater Control Circuit High (Bank 1 Sensor 1): Wiring Diagram
WARNING: This page is about a different car, the 2004 Toyota RAV4. However, it is still accessible from the selected car via links, so may be relevant.
Refer to WIRING DIAGRAM under DTC P2195: OXYGEN (A/F) SENSOR SIGNAL STUCK LEAN (BANK 1 SENSOR 1), DTC P2196: OXYGEN (A/F) SENSOR SIGNAL STUCK RICH (BANK 1 SENSOR 1).