Circuit Description

WARNING: This page is about a different car, the 2002 Lexus GS 430. However, it is still accessible from the selected car via links, so may be relevant.

Throttle control motor opens and closes throttle valve as commanded by ECM. ECM determines throttle valve position using throttle position sensor. If DTC P1128 is set, ECM shuts down power to throttle control motor and electromagnetic clutch.

DTC P1128 is set when throttle control motor locks. Possible causes are:

Faulty throttle control motor.
Faulty throttle body assembly.