DTC P0771: Shift Solenoid "E" Performance (Shift Solenoid Valve SR) [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 TCM detects the actual gear based on signals from the transmission revolution sensors (SP2, NC3 and NT).

Based on the detected gear and oil pressure switch output, the TCM detects related mechanical problems in the shift solenoid valves, valve body and automatic transmission.

HINT:

ACTUAL GEAR SHIFT POSITION WHEN A PROBLEM OCCURS IN SHIFT SOLENOID VALVE SR:

TCM commanded gear	1st	2nd	3rd	4th	5th	6th	7th	8th
Actual gear during SR stuck OFF malfunction 1	7th	7th	7th	7th	7th	7th	7th	7th
Actual gear during SR stuck OFF malfunction 2	3rd	3rd	3rd	3rd	7th	7th	7th	7th

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory
P0771	Shift Solenoid "E" Performance (Shift Solenoid Valve SR)	1. Diagnosis Condition, 2. Malfunction Status, 3. Malfunction Time, 4. Other DTC Detection Condition 1: 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 gear shifts to 5th to 8th are requested by the TCM, the engine speed overruns (neutral status) Malfunction status continues for 0.5 sec. or more (1 trip) 2-trip detection logic DTC Detection Condition 2: 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) One of following occurs: (a) When gear shifts to 1st are requested by the TCM, actual gear changes to 3rd gear (b) When gear shifts to 2nd are requested by the TCM, actual gear changes to 3rd gear (c) When gear shifts to 4th are requested by the TCM, actual gear changes to 3rd gear (d) When gear shifts to 5th are requested by the TCM, actual gear changes to 7th gear (e) When gear shifts to 6th are requested by the TCM, actual gear changes to 7th gear (f) When gear shifts to 8th are requested by the TCM, actual gear changes to 7th gear Malfunction status occurs 2 times per trip 2-trip detection logic	DTC Detection Condition 1: Shift solenoid valve SL2 Shift solenoid valve SR Shift solenoid valve SLT Valve body assembly Torque converter assembly Automatic transmission assembly DTC Detection Condition 2: Shift solenoid valve SL3 Shift solenoid valve SR Valve body assembly Torque converter assembly Automatic transmission assembly	Comes on	DTC stored

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P0771

Shift Solenoid "E" Performance (Shift Solenoid Valve SR)

1. Diagnosis Condition, 2. Malfunction Status, 3. Malfunction Time, 4. Other
DTC Detection Condition 1:

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 gear shifts to 5th to 8th are requested by the TCM, the engine speed overruns (neutral status)
Malfunction status continues for 0.5 sec. or more (1 trip)
2-trip detection logic

DTC Detection Condition 2:

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)
One of following occurs:
(a) When gear shifts to 1st are requested by the TCM, actual gear changes to 3rd gear

(b) When gear shifts to 2nd are requested by the TCM, actual gear changes to 3rd gear

(c) When gear shifts to 4th are requested by the TCM, actual gear changes to 3rd gear

(d) When gear shifts to 5th are requested by the TCM, actual gear changes to 7th gear

(e) When gear shifts to 6th are requested by the TCM, actual gear changes to 7th gear

(f) When gear shifts to 8th are requested by the TCM, actual gear changes to 7th gear
Malfunction status occurs 2 times per trip
2-trip detection logic

DTC Detection Condition 1:

Shift solenoid valve SL2
Shift solenoid valve SR
Shift solenoid valve SLT
Valve body assembly
Torque converter assembly
Automatic transmission assembly

DTC Detection Condition 2:

Shift solenoid valve SL3
Shift solenoid valve SR
Valve body assembly
Torque converter assembly
Automatic transmission assembly

Comes on

DTC stored