Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Circuit Description
Throttle Position (TP) sensor is a variable resistor located on throttle body which monitors throttle opening and delivers input signal to VTA terminal on ECM. Input signal is about .3-1.0 volt with throttle fully closed and about 2.7-5.2 volts with throttle fully open. ECM uses input signal for determining vehicle driving conditions and adjusts air/fuel mixture accordingly. DTC is set when ECM consistently detects less than .1 volt or more than 4.9 volts on VTA circuit. If DTC P0120 exists, ECM will operate in fail-safe mode. Possible causes are:
- TP sensor circuit is open or shorted.
- Defective TP sensor.
- Defective ECM.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.