P0221 code meaning
Throttle/Pedal Position Sensor/Switch B Circuit Range/Performance
Powertrain system Generic code P02xx codes Check engine light
What P0221 means
With electronic throttle control the throttle body carries two position sensors, A and B, usually with opposite or offset signals, and the engine module compares them (correlation code P2135). GM and Ford give the pedal sensors their own codes (P2120 ff), so B is in practice the second throttle sensor. P0221 is the plausibility fault: the signal of sensor B is electrically valid but does not match sensor A or the throttle position expected from airflow. Bosch ME9 engines (Saab) set it at a deviation of more than 9 %, older Ford systems at more than 7 degrees between the sensors without the warning light; many newer engines report this only as P2135. The module carries on with sensor A, limits throttle opening and power and switches off cruise control.
P0221 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0221
- Check engine light on
- Limp mode, reduced power
- Rough idle, jerking
- Cruise control disabled
Common causes of P0221
- Most likelyWorn track of sensor B (signal jumps)
- PossibleContact resistance at connector or wiring
- PossibleThrottle dirty or sticking
- Less likelyMass airflow sensor fault or false air
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Throttle position sensor bElectronic throttle bodySensor wiring
What each part of P0221 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 2 | Area: fuel and air metering (injector circuit). |
| 21 | The exact fault in that area. |
What to do next
- Note P0221 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0221
What does P0221 mean?
P0221 means "Throttle/Pedal Position Sensor/Switch B Circuit Range/Performance". With electronic throttle control the throttle body carries two position sensors, A and B, usually with opposite or offset signals, and the engine module compares them (correlation code P2135). It is a generic code, so it means the same on every make.
Is it safe to drive with P0221?
Drive gently and only to a workshop. With P0221 the car can go into limp mode (reduced power) to protect itself.
Will P0221 fail an emissions test?
Yes, it can. P0221 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0221 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P0221 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.