System Description

WARNING: This page is about a different car, the 2017 Lexus RC 350, 2017 Lexus RC 300, 2016 Lexus RC 350, 2016 Lexus RC 300, and 2015 Lexus RC 350. However, it is still accessible from the selected car via links, so may be relevant.

The ECM uses the signals from the throttle position sensor, air-flow meter, transmission revolution sensor (NT), transmission revolution sensor (SP2) and crankshaft position sensor to monitor the engagement condition of the lock-up clutch.

The ECM compares the engagement condition of the lock-up clutch with the lock-up schedule in the ECM memory to detect mechanical problems of the shift solenoid valve SLU, valve body and torque converter assembly.

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*a	Spool Valve	*b	Sleeve
*c	Solenoid Coil	*d	Lock-up Operation Pressure
*e	Current Flow to Solenoid	-	-

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory
P2757	Torque Converter Clutch Pressure Control Solenoid Performance (Shift Solenoid Valve SLU)	1. Diagnosis Condition 2. Malfunction Status 3. Malfunction Time 4. Other OFF malfunction Engine coolant temperature is 40°C (104°F) or more, ATF temperature is 10°C (50°F) or more and the vehicle is driven with the shift lever in D (no malfunctions are detected in the shift solenoid valve S1, S2, S3, S4, SR, SL1 and SL2, transmission revolution sensors (NT, SP2), coolant temperature sensor, knock control sensor, electronic throttle). When the ECM commands lock-up ON, lock-up does not occurred. 0.4 seconds or more 2-trip detection logic ON malfunction Engine coolant temperature is 40°C (104°F) or more, ATF temperature is 10°C (50°F) or more and the vehicle is driven with the shift lever in D (no malfunctions are detected in the shift solenoid valve S1, S2, S3, S4, SR, SL1 and SL2, transmission revolution sensors (NT, SP2), coolant temperature sensor, knock control sensor, electronic throttle). When the ECM commands lock-up OFF, lock-up remains ON. 1.8 seconds 2-trip detection logic	Shift solenoid valve SLU remains open or closed Transmission valve body assembly is blocked Torque converter assembly Automatic transmission with transfer assembly (clutch, brake, gear, etc.) Line pressure is too low	Comes on	DTC stored

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P2757

Torque Converter Clutch Pressure Control Solenoid Performance (Shift Solenoid Valve SLU)

1. Diagnosis Condition 2. Malfunction Status 3. Malfunction Time 4. Other

OFF malfunction

Engine coolant temperature is 40°C (104°F) or more, ATF temperature is 10°C (50°F) or more and the vehicle is driven with the shift lever in D (no malfunctions are detected in the shift solenoid valve S1, S2, S3, S4, SR, SL1 and SL2, transmission revolution sensors (NT, SP2), coolant temperature sensor, knock control sensor, electronic throttle).
When the ECM commands lock-up ON, lock-up does not occurred.
0.4 seconds or more
2-trip detection logic

ON malfunction

Engine coolant temperature is 40°C (104°F) or more, ATF temperature is 10°C (50°F) or more and the vehicle is driven with the shift lever in D (no malfunctions are detected in the shift solenoid valve S1, S2, S3, S4, SR, SL1 and SL2, transmission revolution sensors (NT, SP2), coolant temperature sensor, knock control sensor, electronic throttle).
When the ECM commands lock-up OFF, lock-up remains ON.
1.8 seconds
2-trip detection logic

Shift solenoid valve SLU remains open or closed
Transmission valve body assembly is blocked
Torque converter assembly
Automatic transmission with transfer assembly (clutch, brake, gear, etc.)
Line pressure is too low

Comes on

DTC stored