DTC P2237-11: A/F (O2) Sensor Positive Current Control Bank 1 Sensor 1 Circuit Short to Ground; DTC P2237-12: A/F (O2) Sensor Positive Current Control Bank 1 Sensor 1 Circuit Short to Battery; DTC P2237-13: A/F (O2) Sensor Positive Current Control Bank 1 Sensor 1 Circuit Open; DTC P2237-16: A/F (O2) Sensor Positive Current Control Bank 1 Sensor 1 Circuit Voltage Below Threshold; DTC P2237-17: A/F (O2) Sensor Positive Current Control Bank 1 Sensor 1 Circuit Voltage Above Threshold; DTC P2237-1B: A/F (O2) Sensor Positive Current Control Bank 1 Sensor 1 Circuit Resistance Above Threshold; DTC P2251-11: O2 Sensor Negative Current Control Bank 1 Sensor 1 Circuit Short to Ground; DTC P2251-12: O2 Sensor Negative Current Control Bank 1 Sensor 1 Circuit Short to Battery [10/2022 - 11/2023]: Procedure

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

HINT: 

Make sure that the connector is properly connected. If it is not, securely connect it and check for DTCs again.

1. Disconnect the air fuel ratio sensor (sensor 1) 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
   C45-3 (A1A+) - Body ground	Ignition switch ON	2.8 to 3.0 V
   C45-4 (A1A-) - Body ground	Ignition switch ON	2.3 to 2.7 V
   C45-3 (A1A+) - C45-4 (A1A-)	Ignition switch ON	0.1 to 0.7 V

   HINT: 

   Perform "Inspection After Repair" after replacing the air fuel ratio sensor (sensor 1).

   Refer to INITIALIZATION [10/2021 - ]

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE AIR FUEL RATIO SENSOR (SENSOR 1) 

Refer to REMOVAL [12/2019 - ]

Result: 

NG 

See step  2

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   C45-1 (HA1A) - C55-9 (HA1A)	Always	Below 1 Ω
   C45-3 (A1A+) - C55-95 (A1A+)	Always	Below 1 Ω
   C45-4 (A1A-) - C55-94 (A1A-)	Always	Below 1 Ω
   C45-1 (HA1A) or C55-9 (HA1A) - Body ground and other terminals	Always	10 kΩ or higher
   C45-3 (A1A+) or C55-95 (A1A+) - Body ground and other terminals	Always	10 kΩ or higher
   C45-4 (A1A-) or C55-94 (A1A-) - Body ground and other terminals	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE ECM 

Refer to REMOVAL [10/2022 - 11/2023]

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR