DTC P0037: Oxygen Sensor Heater Control Circuit Low (Bank 1 Sensor 2), DTC P0038: Oxygen Sensor Heater Control Circuit High (Bank 1 Sensor 2): 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 P0136: OXYGEN SENSOR CIRCUIT MALFUNCTION (BANK 1 SENSOR 2).