What Does P0221 Mean?
This code indicates the throttle/pedal position sensor/switch B circuit output is not within the expected range or is not tracking proportionally with sensor A. The ECM expects sensors A and B to have a defined relationship; when TPS B deviates from expected values relative to TPS A, this range/performance code sets. The signal may be offset, sluggish, or noisy.
Common Causes
40%
Worn throttle position sensor B resistive track causing signal offset or dead spots that differ from the expected relationship with TPS A
25%
Carbon or dirt buildup on the throttle blade or bore causing the blade position to not match sensor output accurately
20%
High-resistance connection or intermittent contact in the TPS B signal circuit causing a voltage offset
15%
ECM internal calibration drift on the TPS B input channel
Diagnostic Steps
1
Step 1: Graph TPS A and TPS B voltages simultaneously while slowly sweeping the throttle from closed to wide open and back. TPS B should track in a smooth, predictable relationship with TPS A (usually inverse or offset). Any deviation, hesitation, or dead spot indicates sensor degradation.
2
Step 2: Clean the throttle body with a proper throttle body cleaner, removing carbon deposits from the blade and bore. A binding throttle blade can cause sensor tracking issues.
3
Step 3: After cleaning, perform a throttle body relearn/idle reset procedure and recheck for the code.
4
Step 4: Measure TPS B signal wire voltage at the ECM connector while sweeping the throttle. This verifies the wiring is not adding resistance or creating a voltage offset.
5
Step 5: If TPS B still shows range/performance deviation after cleaning and wiring checks, replace the throttle body (integrated sensor design) and perform the relearn procedure.
Estimated Repair Cost
$150 - $600
Parts + labor, varies by vehicle and location
This code indicates the throttle/pedal position sensor/switch B circuit output is not within the expected range or is not tracking proportionally with sensor A. The ECM expects sensors A and B to have a defined relationship; when TPS B deviates from expected values relative to TPS A, this range/perf...
The most common cause of P0221 (Throttle/Pedal Position Sensor/Switch B Circuit Range/Performance Problem) is: Worn throttle position sensor B resistive track causing signal offset or dead spots that differ from the expected relationship with TPS A
Typical repair costs for P0221 range from $150 to $600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
A TPS B range/performance fault may activate reduced power mode, limiting vehicle speed and throttle response. This is a safety measure but creates a sudden change in vehicle behavior that the driver should be aware of.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0221 to identify the root cause.
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Quick Info
Category
Powertrain
System
Electronic Throttle Control System
Difficulty
Type
Generic (SAE)
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