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.
Theory Of Operation
The Electronic Throttle Control (ETC) system uses two Throttle Position Sensors (TPS) to monitor the throttle blade position. TPS 1 and TPS 2 are located within the Throttle Body assembly. Each sensor has its own Signal circuit (TPS 1 or TPS 2). Both sensors share a common 5-Volt Reference circuit (Supply) and a common Sensor Ground. Each Signal circuit provides the Powertrain Control Module (PCM) with a signal voltage proportionate to throttle blade movement. Normally operating sensor signals are opposing to each other in the following manner:
- TPS 1 voltage starts low, approximately 0.5 volts at closed throttle, and increases to approximately 4.5 volts at wide open throttle .
- TPS 2 voltage starts high, approximately 4.3 volts at closed throttle, and decreases to approximately 0.7 volts at wide open throttle .
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.