DTC P2100-18: Throttle Actuator "A" Control Motor Circuit Current Below Threshold; DTC P2100-19: Throttle Actuator "A" Control Motor Circuit Current Above Threshold [11/2021 - ]: Fail-Safe
WARNING: This page is about a different car, the 2025 Lexus NX 350, 2024 Lexus NX 350, 2023 Lexus NX 350, and 2022 Lexus NX 350. However, it is still accessible from the selected car via links, so may be relevant.
When these DTCs are stored, the ECM enters fail-safe mode. During fail-safe mode, the ECM cuts the current to the throttle actuator, and the throttle valve is returned to a 9° throttle valve opening angle by the return spring. The ECM then adjusts the engine output by controlling the fuel injection (intermittent fuel-cut) and ignition timing, in accordance with the accelerator pedal opening angle, to allow the vehicle to continue running at a minimal speed. If the accelerator pedal is depressed firmly and gently, the vehicle can be driven slowly.
Fail-safe mode continues until a pass condition is detected, and the ignition switch is turned off.