DTC P0520-12: Engine Oil Pressure Sensor/Switch "A" Circuit Short to Battery; DTC P0520-14: Engine Oil Pressure Sensor/Switch "A" Circuit Short to Ground or Open [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 oil pressure 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
   C11-3 (VC) - Body ground	Ignition switch ON	4.5 to 5.5 V
   C11-1 (POUT) - Body ground	Ignition switch ON	Below 0.1 V

4. Turn the ignition switch off and wait for at least 30 seconds.
5. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   C11-1 (POUT) - C11-2 (GND)	Ignition switch off	190 to 210 kΩ
   C11-2 (GND) - Body ground	Always	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE OIL PRESSURE AND TEMPERATURE SENSOR 

Refer to REMOVAL [12/2019 - ]

Result: 

NG 

See step  2

1. Disconnect the oil pressure sensor 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
   C11-2 (GND) - C55-100 (EPEO)	Always	Below 1 Ω
   C11-1 (POUT) - C55-122 (PEO)	Always	Below 1 Ω
   C11-3 (VC) - C55-99 (VCPE)	Always	Below 1 Ω
   C11-1 (POUT) or C55-122 (PEO) - Body ground and other terminals	Always	10 kΩ or higher
   C11-3 (VC) or C55-99 (VCPE) - Body ground and other terminals	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE ECM 

Refer to REMOVAL [11/2023 - ]

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR