P0121 - Throttle/Pedal Position Sensor/Switch A Range/Performance

TPS/APP signal is outside expected range.

Code Overview

TPS/APP signal is outside expected range.

Common Causes

• TPS/APP sensor drift
• Throttle body sticking
• Wiring issue

Diagnostic Steps

1. Check live data for dropouts
2. Inspect throttle plate for carbon
3. Verify connector pins tight

Likely Repairs & Cost Guides

Use test results to confirm the fault before pricing the repair.

Related OBD Codes

Browse the closest code-family pages when the same fault pattern often shows up nearby.

Next Steps

Move from the code to a diagnosis path, then into repair pricing once the fault is confirmed.