Engine-Codes - Ford - P0121 2002 Ford F150

P0121 2002 Ford F150 Code - Throttle/Pedal Position Sensor/Switch 'A' Circuit Range/Performance

- Code Popularity: 4,256 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 2/3
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What are the Possible Causes of the DTC P0121 2002 Ford F150?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Binding throttle linkage
  • Faulty throttle position sensor
  • Throttle position sensor harness is open or shorted
  • Throttle position sensor circuit poor electrical connection
  • Faulty Engine Control Module (ECM)

Code Tech Notes

The TP sensor circuit is monitored by the PCM for a non closed throttle position at idle. If key ON engine running self-test terminates upon placing the transmission range selector in gear (DRIVE or REVERSE) or when closing the throttle (idle) after opening it (in PARK or NEUTRAL) the TP closed throttle position is not attained, the test fails.

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How to Fix the DTC P0121 2002 Ford F150?

Check the 'Possible Causes' listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.

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What is the Cost to Diagnose the Code?

Labor: 1.0

The cost to diagnose the P0121 2002 Ford F150 code is 1.0 hour of labor. The diagnosis time and labor rates at auto repair shops vary depending on the location, make and model of the vehicle, and even the engine type. Most auto repair shops charge between $75 and $150 per hour.

When is the Code Detected?

Malfunction is detected when an excessively low or high voltage from the sensor is sent to ECM.

What are Code Possible Symptoms?

  • Engine Light ON (or Service Engine Soon Warning Light)

What Does the P0121 2002 Ford F150 Code Mean?

The throttle position sensor (TPS) responds to the accelerator pedal movement. This sensor is a kind of potentiometer which transforms the throttle position into output voltage, and emits the voltage signal to the Engine Control Module (ECM). In addition, the sensor detects the opening and closing speed of the throttle valve and feeds the voltage signal to the ECM.
Idle position of the throttle valve is determined by the ECM receiving the signal from the throttle position sensor. This sensor controls engine operation such as fuel cut. On the other hand, the Wide open and closed throttle position switch, which is built into the throttle position sensor unit, is not used for engine control.

P0121 2002 Ford F150 Code - Throttle/Pedal Position Sensor/Switch 'A' Circuit Range/Performance

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