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 Engine Control Module (ECM) controls engine speed by adjusting the position of the throttle control valve (DC motor). The throttle motor is a DC motor driven by one coil. The ECM applies current to the DC motor coil in PWM (%) to adjust the throttle valve into a passage in the throttle body to allow air flow. This method allows highly accurate control of engine speed and quick response to changes in engine load.
- The acceleration position (AP1) sensor circuit provides a voltage signal relative to acceleration pedal angle.
The acceleration pedal angle will vary about 0.65V at idle position to about 4.35V at wide open throttle (WOT).
APS signal is used to determine which DC motor will adjust throttle position.
After the APS signal has been processed by the ECM, it will command DC motor to allow movement of throttle position.
Use the Manual With the Right Hardware
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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.