DTC P0873: Transmission Fluid Pressure Sensor / Switch "C" Circuit High [11/2021 - ]: Description

WARNING: This page is about a different car, the 2024 Lexus IS 500, 2023 Lexus IS 500, and 2022 Lexus IS 500. However, it is still accessible from the selected car via links, so may be relevant.

The oil pressure switch, which is built into the valve body, detects the fluid pressure of the SL1 fluid pressure circuit. If shift solenoid valve SL1 is stuck ON, P0873 is output.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory
P0873	Transmission Fluid Pressure Sensor / Switch "C" Circuit High	1. Diagnosis Condition 2. Malfunction Status 3. Malfunction Time 4. Other Engine coolant temperature is 40°C (104°F) or more, ATF temperature is -10°C (14°F) or more, and the vehicle is driven with the shift lever in D (no malfunctions are detected in shift solenoid valve SL1, 2, 3, 4 and 5, SR, transmission revolution sensors (NT, NC3, SP2), water temperature sensor, oil temperature sensor, knock control sensor, electronic throttle, or CAN2) When the actual gear is 6th to 8th gear, the oil pressure switch is ON Malfunction status occurs 2 times (1 trip) 2-trip detection logic	Shift solenoid valve SL1 Oil pressure switch Transmission wire Harness and connector TCM Valve body assembly Automatic transmission assembly	Comes on	DTC stored