DTC P0766: Shift Solenoid "D" Performance (Shift Solenoid Valve S4); DTC P0776: Pressure Control Solenoid "B" Performance (Shift Solenoid Valve SL2) [09/2014 - 11/2017]: 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 signals from the transmission revolution sensor (SP2) and transmission revolution sensor (NT) to detect the actual gear position (1st, 2nd, 3rd, 4th, 5th or 6th gear).

Then the ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical problems of the shift solenoid valves, valve body or automatic transmission (clutch, brake, gear, etc.).

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory
P0766	Shift Solenoid "D" Performance (Shift Solenoid Valve S4)	1. Diagnosis Condition 2. Malfunction Status 3. Malfunction Time 4. Other S4 stuck OFF malfunction or brake control valve malfunction* Engine coolant temperature is 40°C (104°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). Both of the following conditions (a) and (b) are met: When the ECM commands the transmission to shift to 5th gear, the actual gear is shifted to 4th. When the ECM commands the transmission to shift to 6th gear, the actual gear is shifted to 4th. 0.4 seconds 2-trip detection logic	Shift solenoid valve S4 remains closed Shift solenoid valve SLT remains open or closed Transmission valve body assembly is blocked (Brake control valve) Automatic transmission with transfer assembly (clutch, brake, gear, etc.)	Comes on	DTC stored
P0776	Pressure Control Solenoid "B" Performance (Shift Solenoid Valve SL2)	1. Diagnosis Condition 2. Malfunction Status 3. Malfunction Time 4. Other SL2 stuck ON malfunction or brake control valve malfunction* Engine coolant temperature is 40°C (104°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). Both of the following conditions (a) and (b) are met: When the ECM commands the transmission to shift to 5th gear, the actual gear is shifted to 4th. When the ECM commands the transmission to shift to 6th gear, the actual gear is shifted to 4th. 0.4 seconds 2-trip detection logic	Shift solenoid valve SL2 remains open Shift solenoid valve SLT remains open or closed Valve body is blocked (Brake control valve) Automatic transmission (clutch, brake, gear, etc.)	Comes on	DTC stored

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

P0766

Shift Solenoid "D" Performance (Shift Solenoid Valve S4)

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

S4 stuck OFF malfunction or brake control valve malfunction*

Engine coolant temperature is 40°C (104°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).
Both of the following conditions (a) and (b) are met:
1. When the ECM commands the transmission to shift to 5th gear, the actual gear is shifted to 4th.
2. When the ECM commands the transmission to shift to 6th gear, the actual gear is shifted to 4th.
0.4 seconds
2-trip detection logic

Shift solenoid valve S4 remains closed
Shift solenoid valve SLT remains open or closed
Transmission valve body assembly is blocked (Brake control valve)
Automatic transmission with transfer assembly (clutch, brake, gear, etc.)

Comes on

DTC stored

P0776

Pressure Control Solenoid "B" Performance (Shift Solenoid Valve SL2)

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

SL2 stuck ON malfunction or brake control valve malfunction*

Engine coolant temperature is 40°C (104°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).
Both of the following conditions (a) and (b) are met:
1. When the ECM commands the transmission to shift to 5th gear, the actual gear is shifted to 4th.
2. When the ECM commands the transmission to shift to 6th gear, the actual gear is shifted to 4th.
0.4 seconds
2-trip detection logic

Shift solenoid valve SL2 remains open
Shift solenoid valve SLT remains open or closed
Valve body is blocked (Brake control valve)
Automatic transmission (clutch, brake, gear, etc.)

Comes on

DTC stored

HINT:

Gear positions in the event of a solenoid valve mechanical problem:

ECM command gearshift	1st	2nd	3rd	4th	5th	6th
*: Actual gear position under malfunction	1st	2nd	3rd	4th	4th	4th

Gear position during fail-safe operation:

If any malfunction is detected, the ECM changes into the fail-safe mode to shift into the gear positions as shown in the table below.

Gear position under normal conditions	1st	2nd	3rd	4th	5th	6th
*: Actual gear position under fail-safe mode	1st	2nd	3rd	3rd	3rd	3rd