P0221
Throttle/Pedal Position Sensor/Switch B Circuit Range/Performance
Throttle / pedal position
Generic OBD-II
High
What it means
P0221 sets when the signal from throttle- or accelerator-pedal position sensor B is present but outside its expected range, or doesn't track the other position signals. Because the ECM can't fully trust the throttle demand, it often drops the engine into a reduced-power (limp) mode to keep things safe.
High
Can I keep driving? Often yes, but the car may drop into reduced-power mode and feel sluggish or erratic — drive gently and fix it before depending on full throttle.
Common symptoms
What you'll notice
- Check-engine light on
- Reduced engine power or 'limp' mode
- Hesitation, surging, or stumble on acceleration
- Erratic or unstable idle
Common causes
Most likely first
- Failed throttle- or pedal-position sensor BLikely
- Damaged, chafed, or shorted wiring in the sensor circuitCommon
- Loose or corroded sensor connectorCommon
- Rarely, a failed ECM/PCMLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame and check for companion codes (P0220, P0222, P0223) to confirm which circuit is at fault.
- Inspect the sensor connector and wiring for damage, corrosion, or a loose pin, and repair as needed.
- Back-probe the sensor signal, 5V reference, and ground against spec while slowly sweeping the pedal or throttle.
- If wiring and signals check out, replace the throttle-body or accelerator-pedal position sensor.
- Clear the code and road-test to confirm the fault is gone.
FAQ
Quick answers
Is it safe to drive with P0221?+
It can trigger reduced-power mode, making the car slow and unpredictable on acceleration. Short, careful trips are usually possible, but get it diagnosed before relying on it in traffic.
Can I just clear P0221?+
It will clear, but if the sensor or wiring is still out of range the ECM resets it — often the same drive — and may re-enter limp mode.
Related codes
Often seen with P0221
Read & clear P0221 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX