Possible Causes

WARNING: This page is about a different car, the 2003 Toyota Camry. However, it is still accessible from the selected car via links, so may be relevant.

Possible causes are:

DTC P2102

If throttle control motor output duty is greater than or equal to 80% and throttle control motor current is less than 0.5 A and this continues for 2 seconds.

DTC P2103

If throttle control motor current is greater than or equal to 10 A.

DTC P2103

If throttle control motor current is greater than or equal to 7 A for 0.6 seconds.
Open or short in throttle control motor circuit.
Defective throttle body assembly (throttle motor).
Defective ECM.