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.

Throttle motor is operated by the ECM and it opens and closes the throttle valve. The opening angle of the throttle valve is detected by the throttle position sensor which is mounted on the throttle body. It provides feedback to the ECM to control the throttle motor in order to adjust throttle valve opening angle properly in response to driving condition. If these DTCs are stored, the ECM shuts down the power to the throttle motor, and the throttle valve is locked at a certain opening angle. DTCs are set when throttle control motor output duty is 80 percent or more and throttle control motor current is less than .5 amps, throttle control motor current is 16 amps or more, or throttle control motor current is 7 amps or more for more than .9 seconds. See Fig 1. Possible causes are:

Open or short in throttle control motor circuit.
Faulty throttle control motor.
Faulty ECM.

Fig 1: Identifying Throttle Actuator Control Motor Circuits