The P0759 code in your 2021 Lexus ES indicates an intermittent problem with shift solenoid B. The solenoid works sometimes but fails or behaves erratically at other times. Your ES uses an 8-speed automatic transmission where this inconsistent operation affects specific gear shifts.
Intermittent Shift Solenoid Behavior
An intermittent solenoid works fine for periods then fails unpredictably. Shifts controlled by solenoid B may be smooth one trip and harsh the next. The TCM recognizes this pattern of inconsistent operation and stores P0759.
Common Causes
Loose electrical connections at the transmission connector. Wiring with damaged insulation creating intermittent contact. A solenoid that's partially failing—works under some conditions but not others. Corroded terminals causing inconsistent contact. Temperature-related issues affecting the solenoid.
Symptoms in Your ES
Shift quality varies unpredictably in gears controlled by solenoid B. The check engine light may come on and off. Symptoms may correlate with temperature, driving conditions, or time. Frustrating inconsistency characterizes this code.
Lexus Diagnostic Approach
Using Toyota/Lexus Techstream, monitor shift solenoid B operation over extended driving. Note when problems occur and what conditions exist. Wiggle test connections while monitoring. Drive in various conditions to trigger the intermittent behavior. Check all terminals for proper tension and cleanliness.