Circuit Description

WARNING: This page is about a different car, the 2003 Lexus GS 300. 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 this DTC is stored, the throttle valve is locked at a certain opening angle. Also, the whole electronically controlled throttle operation is cancelled until the system returns to normal and the ignition switch is turned OFF. DTCs are set when throttle control motor output duty is greater than 80 percent and throttle control motor current is less than 0.5 amp for 2 seconds, throttle control motor current is greater than 16 amps, or throttle control motor current is greater than 7 amps for .6 second. See Fig 1. Possible causes are:

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

Fig 1: Identifying Throttle Actuator Control Motor Circuits