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
The Throttle Position (TP) sensor is a 2 variable resistor sensor that monitors throttle opening and TP sensor malfunction. Based on TP sensor signal, ECM determines vehicle driving condition and uses throttle control motor to set throttle angle accordingly. If DTC P0120 is set, ECM shuts down power to throttle control motor and electromagnetic clutch.
DTC P0120 is set when ECM consistently detects .2 volt or less, or 4.8 volts or more from VTA circuit, or .5 volt or less from VTA2 circuit for 2 seconds. DTC P0120 is also set when ECM consistently detects .2 volt or more and 2.0 volts or less from VTA circuit, and 4.97 volts or more from VTA2 circuit for 2 seconds.
DTC P0120 is also set when ECM consistently detects .02 volt or less from VTA and VTA2 circuit for 2 seconds. DTC P0120 is also set when ECM consistently detects .2 volt or less from VTA circuit and .5 volt or less from VTA2 circuit for .4 second. Possible causes are:
- Open or short in TP sensor circuit.
- Faulty TP sensor.
- Faulty ECM.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
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.