This code indicates that the engine computer has detected an abnormally low voltage in the 'B' circuit of the throttle or accelerator pedal position sensor. Because modern vehicles use redundant sensors for safety, a low voltage on this specific circuit means the computer cannot accurately verify the driver's throttle input, often triggering a failsafe mode.
Internal sensor failure is the most common cause, resulting in a dropped or missing voltage signal on the B circuit.
Chafed wires, corroded terminals, or loose connections can ground out the signal wire, causing the low voltage condition.
Heavy soot can prevent the throttle plate from fully closing, which alters the sensor's resting voltage and triggers the code.
A faulty engine computer may fail to read the voltage correctly, though this is extremely rare compared to sensor or wiring failures.
It is not recommended. The vehicle will likely enter limp mode, severely restricting speed and acceleration, which can be dangerous in traffic.
Rarely. Drivers are often told to replace the PCM for this code, but that is usually incorrect. P0222 is almost always caused by a failed sensor, damaged wiring, or poor connections. The PCM should be the absolute last component tested or replaced.
Modern electronic throttle systems use two or more position sensors for redundancy. The 'B' circuit refers to the secondary sensor, which the computer uses to cross-check the primary 'A' circuit for safety.
Yes. Excessive carbon buildup can prevent the throttle plate from returning to its proper resting position, altering the sensor's voltage reading enough to trigger a low voltage code.