General Information

Engine Control
P0121 Throttle Position Sensor 1 Signal Circuit Range/Performance - General Information

Component Location





General Description

The Electronic Throttle Control (ETC) system consists of the throttle body, Throttle Position Sensor (TPS) 1 & 2 and Accelerator Position Sensor (APS) 1 & 2. TPS 1 & 2 share the same source voltage and ground. The PCM controls the throttle motor to open and close the throttle valve. The TPS1 output voltage increases in proportion with the throttle valve opening after starting. TPS2 output voltage decreases in proportion with the throttle valve opening angle after starting. The TPS provides feedback to the PCM to control the throttle motor in response to the APS.

DTC Description

PCM monitors output signals from TPS 1 and 2. If output signals differ between TPS1 and TPS2 by more than 8% for one drive cycle, the PCM sets a P0121 DTC.

DTC Detecting Condition





Specification





Diagnostic Circuit Diagram





Signal Waveform & Data












Fig.1) Normal data and waveform of TPS1 & TPS2 with depressing accel. pedal.
Fig.2) Normal data and waveform of TPS1 & TPS2 with pressing accel. pedal.
Fig.3) Abnormal data of TPS1 & TPS2 with connector disconnected condtion.