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Home >> Toyota >> 2004 >> Matrix Base, FWD, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 79 (Engine Controls - Self-Diagnostics) >> Diagnostic Tests >> DTC P1129: Electronic Throttle Control System (ETCS) Malfunction >> Diagnosis & Repair
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Diagnosis & Repair

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

Retrieve trouble codes. See RETRIEVING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. If other codes are displayed, diagnose and repair those codes first and retest. If only DTC P1129 is displayed, go to next step. Clear and retrieve trouble codes. If DTC P1129 is displayed again, replace throttle body and retest.

Check throttle control motor for operating sound. Turn ignition on. When turning accelerator pedal position sensor lever, check running sound of motor. Ensure there is no friction sound. Check accelerator pedal position sensor with scan tool. Standard throttle valve opening percentage is 60 percent or more. If not to specification, check sensor, wiring and ECM. If all components are okay, replace ECM.

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