DTC P0840-87: Transmission Fluid Pressure Sensor/Switch "A" Missing Message [09/2023 - ]: Procedure
WARNING: This page is about a different car, the 2024 Lexus TX 500h. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - TCM)
Pre-procedure1
- Disconnect the transmission wire connector.
- Disconnect the TCM connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition Result C65-2 (VC) - C25-51 (VCPT) Always Below 1 Ω Ω C65-1 (PTO) - C25-48 (PTO) Always Below 1 Ω Ω C65-3 (EPTO) - C25-47 (EPTO) Always Below 1 Ω Ω C65-2 (VC) or C25-51 (VCPT) - other terminals Always 10 kΩ or higher kΩ C65-1 (PTO) or C25-48 (PTO) - other terminals Always 10 kΩ or higher kΩ C65-3 (EPTO) or C25-47 (EPTO) - other terminals Always 10 kΩ or higher kΩ Result
Proceed to OK NG
Post-procedure1
- None.
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 2
- CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - TCM)
Pre-procedure1
- Disconnect the transmission wire connector.
- Turn the ignition switch to ON.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition Result C65-2 (VC) - C65-3 (EPTO) Ignition switch ON 4.89 to 5.11 V V C65-1 (PTO) - C65-3 (EPTO) Ignition switch ON 4.89 to 5.11 V V
Pre-procedure2
- Turn the ignition switch off.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition Result C65-3 (EPTO) - Body ground Always Below 1 Ω Ω Result
Proceed to OK NG
Post-procedure1
- None.
Result:
NG
REPLACE TCM. Refer to REMOVAL [09/2023 - ]
Result:
OK
See step 3
- CHECK HARNESS AND CONNECTOR (TRANSMISSION WIRE - OIL PRESSURE SENSOR)
Pre-procedure1
- Disconnect the transmission wire connector.
- Disconnect the oil pressure sensor connector.
HINT:
Refer to REMOVAL [09/2023 - ]
- Measure the resistance according to the value(s) in the table below.
*1 Transaxle Assembly with Motor *2 Oil Pressure Sensor *3 Transmission Wire - - *a Oil Pressure Sensor Side *b Wire Harness Connector Side Standard Resistance
Tester Connection Condition Specified Condition Result Terminal 1 of the oil pressure sensor connector - C65-1 (PTO) Always Below 1 Ω Ω Terminal 2 of the oil pressure sensor connector - C65-2 (VC) Always Below 1 Ω Ω Terminal 3 of the oil pressure sensor connector - C65-3 (EPTO) Always Below 1 Ω Ω Terminal 1 of the oil pressure sensor connector or C65-1 (PTO) - other terminals Always 10 kΩ or higher kΩ Terminal 2 of the oil pressure sensor connector or C65-2 (VC) - other terminals Always 10 kΩ or higher kΩ Terminal 3 of the oil pressure sensor connector or C65-3 (EPTO) - other terminals Always 10 kΩ or higher kΩ Result
Proceed to OK NG
Post-procedure1
- None.
Result:
OK
REPLACE TRANSAXLE ASSEMBLY WITH MOTOR. Refer to REMOVAL [09/2023 - ]
Result:
NG
REPAIR OR REPLACE TRANSMISSION WIRE. Refer to REMOVAL [09/2023 - ]