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Home >> Toyota >> 2004 >> Matrix Base, 4WD >> Repair and Diagnosis >> External Pages >> Different car >> Section 78 (Engine Control System Self-Diagnostics) >> Diagnostic Tests >> DTC P0121: Throttle Position Sensor Circuit Range/Performance >> Circuit Description
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Circuit Description

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

Throttle Position (TP) sensor is a variable resistor located on throttle body which monitors throttle opening and delivers input signals to Engine Control Module (ECM). ECM uses input signals for determining vehicle driving conditions and adjusts air/fuel mixture accordingly. DTC is set after vehicle speed is more than 19 MPH once and TP sensor output voltage is out of range. Possible cause is defective TP sensor.