LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2015 >> ES 350 >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Control System - Diagnostic Codes & Circuit Tests >> SFI System >> DTC P2121: Throttle / Pedal Position Sensor / Switch "D" Circuit Range / Performance [08/2014 - ] >> Fail-Safe
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC P2121: Throttle / Pedal Position Sensor / Switch "D" Circuit Range / Performance [08/2014 - ]: Fail-Safe

The accelerator pedal sensor assembly has 2 (main and sub) sensor circuits. If a malfunction occurs in either of the sensor circuits, the ECM limits the engine output. If both circuits malfunction, the ECM regards of the accelerator pedal angle as being fully closed. In this case, the throttle valve remains closed as if the engine is idling.

If a pass condition is detected and then the engine switch is turned off, the fail-safe operation stops and the system returns to normal.