P1121 LEXUS Possible Causes
- Faulty accelerator pedal position sensor
- Accelerator pedal position sensor harness is open or shorted
- Poor electrical connection in accelerator pedal position sensor circuit
How to Fix P1121 LEXUS Code?
Start by checking the “Possible Causes” listed above. Visually inspect the corresponding wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.
Possible Symptoms
Illuminated engine light (or service engine soon warning light)
P1121 LEXUS Meaning
The accelerator pedal position sensor is mounted on the throttle body and features 2 sensors to detect throttle position and throttle position malfunction.
The accelerator pedal position sensor is connected to the accelerator pedal via the throttle cable, and the voltage applied across the VPA and VPA2 terminals of the engine control module (ECM) changes between 0 V and 5 V proportionally to the accelerator pedal opening angle.
The ECM calculates the current accelerator pedal opening angle from the input of these signals from the VPA and VPA2 terminals, and the ECM controls the throttle motor based on these signals.
If code P1120 is stored, the ECM cuts power to the throttle motor and magnetic clutch, and the throttle valve is completely closed by the return spring.
However, the throttle valve opening angle can be controlled by the accelerator pedal via the throttle cable.