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): Procedure

1. Inspect the air fuel ratio sensor. Refer to INSPECTION .

NG → See step   5 

OK: Go to next step 

Fig 1: Identifying B16 Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the air fuel ratio sensor connector.
2. Turn the ignition switch to ON.
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   B16-2 (+B) - Body ground	Ignition switch ON	11 to 14 V

4. Reconnect the air fuel ratio sensor connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (AIR FUEL RATIO SENSOR - ENGINE ROOM RELAY BLOCK) 

OK: Go to next step 

1. Disconnect the air fuel ratio sensor connector.
2. Disconnect the ECM connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance (Check for Open)

   Tester Connection	Condition	Specified Condition
   B16-1 (HA1A) - B29-109 (HA1A)	Always	Below 1 Ω

   Standard Resistance (Check for Short)

   Tester Connection	Condition	Specified Condition
   B16-1 (HA1A) or B29-109 (HA1A) - Body ground	Always	10 kΩ or higher

4. Reconnect the air fuel ratio sensor connector.
5. Reconnect the ECM connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (AIR FUEL RATIO SENSOR - ECM) 

OK: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Clear the DTCs. Refer to DTC CHECK / CLEAR .
5. Start the engine.
6. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
7. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
8. Read DTCs.

   Result

   Result	Proceed to
   No output	A
   P0031 or P0032	B

B → See step   6 

A → See step   7