Code result
P0121
Throttle/Pedal Position Sensor/Switch A Circuit Range/Performance
High severity
What it means
The throttle position sensor (TPS) signal does not match the expected range for the commanded pedal position. On drive-by-wire vehicles, two redundant sensors are compared; a divergence between them or implausible motion triggers this code.
Is it safe to drive?
No — stop driving
This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly.
Most likely causes
TPS contact track worn (older potentiometer-type sensors)
highOne of the most commonly reported causes for this code — check this first.
Carbon buildup blocking throttle plate
mediumA plausible cause — test and verify before replacing parts.
Corroded TPS connector
lowLess common, but worth ruling out after the more likely causes.
Related help
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