P0121 Fault Code

Throttle/Pedal Position Sensor/Switch A Circuit Range/Performance Problem

• What does that mean?
• Symptoms
• Causes
• Solutions

The P0121 fault code indicates that there is a problem with the Throttle/Pedal Position Sensor/Switch A Circuit. This sensor monitors the position of the throttle and sends this information to the engine control unit (ECU). If the ECU detects that the throttle position does not match expected values, it triggers the P0121 code.

What are the symptoms of the P0121 code?

• Check Engine Light (CEL) illuminated
• Poor acceleration or hesitation during driving
• Unstable or erratic engine performance
• Reduced fuel efficiency
• Difficulty in maintaining speed
• Idle speed issues or stalling

What causes the P0121 code?

• Faulty throttle position sensor
• Wiring issues or connectors related to the throttle position sensor
• Damaged or corroded terminals
• Problems with the engine control module (ECM)
• Vacuum leaks affecting throttle performance
• Mechanical issues with the throttle body

How to fix P0121?

• Inspect the throttle position sensor for any visible damage or wear
• Test the sensor using a multimeter to check its function and output
• Check wiring and connectors for corrosion or disconnections
• Repair or replace any damaged wiring or faulty connectors
• Clean the throttle body if necessary
• If all else fails, consider replacing the throttle position sensor