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Home >> Toyota >> 1996 >> Tercel Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Tests W/Codes >> Circuit Tests >> DTC P0120 - Throttle Position (TP) Sensor Circuit Malfunction >> Circuit Description
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Circuit Description

The TP sensor is a variable resistor that monitors throttle opening. The ECM determines vehicle driving condition and adjusts air/fuel mixture accordingly. DTC is set when ECM consistently detects less than .1 volt from VTA circuit and closed throttle position switch is on. DTC can also be set if ECM consistently detects 4.9 volts or more. Possible causes are:

NOTE: If DTCs P0105, P0106, P0110, P0115 and P0120 are output together, inspect ECM terminal E2 (ground) circuit. Repair as necessary. See appropriate wiring diagram in WIRING DIAGRAMS article.