Circuit Description

WARNING: This page is about a different car, the 2003 Lexus GS 430. However, it is still accessible from the selected car via links, so may be relevant.

Battery positive voltage is supplied to terminal +BM of the ECM for the electric throttle control system. If this DTC is stored, the ECM shuts down the power for the throttle motor and the electromagnetic clutch, and the throttle valve is fully closed by the return spring. Opening angle of throttle valve can be controlled by accelerator pedal through throttle cable. DTC is set when there is an open circuit in ETCS power source circuit. See Fig 1. Possible causes are:

Open in ETCS power source circuit.
Faulty ECM.

Fig 1: Identifying Throttle Actuator Control Motor Circuits