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 P0121 Throttle/Pedal Position Sensor/Switch "A" Circuit Range/Performance Problem: Description
HINT:
This DTC relates to the Throttle Position (TP) sensor.
Refer to DTC P0120 .
| DTC No. | DTC Detection Conditions | Trouble Areas |
|---|---|---|
| P0121 | Difference between VTA1 and VTA2 voltages less than 0.8 V, or more than 1.6 V for 2 seconds (1 trip detection logic) | TP sensor (built into throttle body) |
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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.
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