Code P2168 indicates that the Engine Control Module (ECM) has detected a performance problem with the 'F' circuit of the throttle/pedal position sensor. This sensor is typically part of the accelerator pedal assembly and provides a signal corresponding to pedal position. The 'Maximum Stop Performance' condition means the sensor signal is stuck at or near the idle position value, often due to a short to ground, open circuit, or sensor failure.
The sensor itself may have internal wear, contamination, or electrical failure causing it to output a fixed low voltage corresponding to idle position regardless of pedal movement.
Wiring between the pedal sensor and ECM may be chafed or pinched, grounding the signal wire and pulling the voltage to near zero, which the ECM interprets as maximum stop.
A broken wire or loose terminal can interrupt the signal, causing the ECM to see a default low voltage and set the code.
Moisture intrusion or bent pins at the pedal connector can create high resistance or intermittent contact, leading to an incorrect signal reading.
The engine control module may have an internal fault in the sensor input circuit, but this is extremely uncommon and should only be considered after exhaustive testing of all other components.
It means the engine computer has detected that the signal from one of the accelerator pedal position sensors (sensor 'F') is stuck at the value that represents the pedal being fully released, even when the pedal is pressed. This prevents normal acceleration.
It is not recommended. The vehicle will likely have no throttle response or be in limp mode, which limits speed and power. Driving could be unsafe, especially in traffic. Have it diagnosed as soon as possible.
No. The ECM is very rarely at fault. Many drivers are mistakenly told to replace the computer, but the problem is almost always the accelerator pedal sensor, wiring, or connector. Replacing the ECM should only be considered after all other possibilities are thoroughly ruled out.
If you have basic mechanical skills and tools, replacing the pedal assembly (which often includes the sensor) is usually straightforward. However, some vehicles require a relearn procedure using a scan tool after replacement. Always consult a service manual for your specific vehicle.