Throttle/Pedal Position Sensor A Circuit Range/Performance Problem

Where it lives

For P0121, the part to look at first is the sensor named here.

Check these first

• Faulty throttle position sensor
• Carbon buildup interfering with throttle movement
• Misadjusted or worn throttle linkage
• Wiring issues or poor connector contact
• Throttle body malfunction

What to do next

1. Check throttle operation for freedom of movement and full range
2. Read TPS voltage at closed, partial, and full throttle with an OBD-II scanner
3. Clean the throttle body if sticking or carboned up
4. Verify TPS connector contacts and wiring
5. Replace the throttle position sensor if out of range

Look up another code