Code P2620 indicates that the engine computer has detected an open circuit in the throttle position sensor output circuit. This means there is a break in the electrical path, preventing the throttle position signal from reaching the computer, which often forces the vehicle into a power-limited failsafe mode.
A broken, chafed, or disconnected wire in the throttle position sensor output circuit is the most common cause of this code.
The sensor itself may have an internal open circuit, failing to generate or send the required voltage signal back to the computer.
Poor contact, pushed-back pins, or corrosion at the sensor or engine computer connector can interrupt the signal path.
An internal failure in the engine computer is extremely rare but can cause an open circuit reading if the internal signal path fails.
An open circuit means there is a break in the electrical path, similar to a cut wire or disconnected plug, which prevents the throttle position signal from traveling to the engine computer.
It is not recommended. The vehicle will likely enter limp mode, severely restricting engine speed and throttle response, which can be hazardous in traffic.
Rarely. Mechanics commonly and mistakenly recommend replacing the engine computer for this code, but the actual cause is almost always a broken wire, poor connection, or a failed throttle position sensor rather than the control module itself.
Without a signal from the throttle position sensor, the engine computer cannot determine how far the throttle plate is open, forcing it to restrict RPMs and disable normal acceleration to prevent engine damage or runaway.