The OBD-II code P0120 indicates a malfunction in the Throttle/Pedal Position Sensor/Switch “A” Circuit. This code is triggered when the engine control module (PCM) detects an issue with the throttle position sensor or the accelerator pedal position sensor.
What Does the P0120 Code Mean?
OBD-II Code P0120 is defined as a Throttle/Pedal Position Sensor/Switch “A” Circuit Malfunction. This code indicates that the PCM has detected an out-of-range value from the throttle or pedal position sensor, which can affect engine performance and drivability.
What Causes the P0120 Code?
- Defective Throttle/Pedal Position Sensor or Switch
- Dirty or carbon-filled Throttle Bore
- Torn or jammed floor mats obstructing the pedal
- Faulty or corroded wiring or connections related to the Throttle/Pedal Position Sensor/Switch
What Are the Symptoms of the P0120 Code?
- Check Engine Light will illuminate
- No noticeable symptoms in many cases
- Hard starting of the engine
- Engine hesitation during acceleration
How Serious Is the P0120 Code?
The P0120 code is considered urgent, as it can lead to significant malfunctions that may cause severe damage to the vehicle or pose safety risks to the driver and passengers. The vehicle may enter a “limp home mode,” restricting speed to 20 mph or less until the issue is resolved.
How to Diagnose the P0120 Code
To diagnose the P0120 code, follow these steps:
- Verify the trouble code using a diagnostic scanner.
- Inspect the data stream from the Throttle Position Sensor and/or Pedal Position Sensor.
- Check the voltage output from the sensors at idle and during acceleration.
- Perform visual inspections of the sensors and wiring for damage or poor connections.
- Conduct a “wiggle test” to see if the wiring affects the voltage readings.
Common Repairs for the P0120 Code
- Replacing a defective Throttle/Pedal Position Sensor or Switch
- Cleaning a dirty or carbon-filled Throttle Body
- Repairing faulty wiring or connections
- Adjusting or replacing obstructive floor mats
How Much Does It Cost to Fix the P0120 Code?
The cost to fix the P0120 code can vary widely depending on the underlying cause. Expect to pay for diagnostic fees, which can range from $100 to $150, along with additional costs for parts and labor if repairs or replacements are necessary. Total costs can range from $200 to $600 or more, depending on the complexity of the issue.
Can I Fix the P0120 Code Myself?
While some vehicle owners may be able to perform simple inspections and cleanings, diagnosing and repairing the P0120 code typically requires technical expertise and specialized tools. If you are unsure about any steps in the process, it is advisable to seek professional assistance to avoid unnecessary repairs and ensure the problem is accurately diagnosed.
