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.
DTC P1654: Service Throttle Soon Light Control Circuit: Description
The SERVICE THROTTLE SOON light is illuminated by PCM if diagnostics have detected certain errors related to Accelerator Pedal Position (APP) sensor. When PCM is commanding SERVICE THROTTLE SOON light on, voltage potential of circuit will be low (about zero volts). When PCM is commanding SERVICE THROTTLE SOON light off, voltage potential of circuit will be high (about battery voltage). PCM supplies ground to SERVICE THROTTLE SOON light control circuit.
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.