Circuit description
Refer to dtc p0120
| Dtc no. | Dtc detection condition | Trouble area |
| P0121 | The following condition is met 4 times. After the vehicle speed has exceeded 30 km/h once, the throttle position sensor output value is out of normal range when the throttle valve is closed at 0 km/h |
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The throttle position sensor varies its resistance with the angle of the throttle valve. The ecm applies a regulated reference voltage to the throttle position sensor “+” terminal and calculates the angle of the throttle valve based on the voltage present at the throttle position sensor “signal” terminal.
When the throttle valve is near the fully closed position, the output voltage of the throttle position sensor is low. When it is near the fully open position, the output voltage is high.
The ecm checks the indicated angle of the throttle valve during “stop and go” conditions. If the indicated angle (or voltage) in the “closed throttle” position is out of the specified range, the ecm interprets this as a malfunction in the throttle position sensor and sets a dtc.
Monitor strategy
”Stop and go” is defined as follows: ”stop” indicates a vehicle speed of 0 km/h. ”Go” indicates a vehicle speed of 30 km/h.
Typical malfunction thresholds
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