DTC P0221: Throttle/Pedal Position Sensor/Switch “B” Circuit Range/Performance

In the intricate world of automotive diagnostics, diagnostic trouble codes (DTCs) serve as invaluable guides, unraveling potential issues within a vehicle’s systems. DTC P0221 takes center stage as a critical indicator of problems related to the Throttle/Pedal Position Sensor/Switch “B” Circuit Range/Performance. This comprehensive article delves into the causes, symptoms, inspection procedures, and effective solutions for diagnosing and resolving DTC P0221.

1. Causes of DTC P0221:

DTC P0221 emerges when the Engine Control Module (ECM) identifies an anomaly in the Throttle/Pedal Position Sensor/Switch “B” circuit’s range or performance. The underlying causes can encompass:

– Faulty throttle or pedal position sensor/switch: A malfunctioning sensor or switch can provide inaccurate readings to the ECM.

– Wiring and connector issues: Damaged or corroded wiring and connectors within the circuit can lead to performance discrepancies.

– Throttle control system issues: Malfunctions within the throttle control system can affect sensor/switch operation.

– ECM malfunction: An erratic ECM can misinterpret sensor/switch data.

2. Symptoms of DTC P0221:

Recognizing the symptoms associated with DTC P0221 aids mechanics in accurate diagnosis:

– Reduced engine power: The engine may operate in a limited power mode to prevent potential issues.

– Delayed throttle response: The vehicle’s response to accelerator pedal input may be delayed.

– Illuminated Check Engine Light (CEL): DTC P0221 triggers the CEL to alert the driver of a Throttle/Pedal Position Sensor/Switch “B” circuit range/performance problem.

3. Inspection of DTC P0221:

Thorough inspection techniques are pivotal for pinpointing the root cause:

– OBD-II scan: Utilize an OBD-II scanner to retrieve the DTC and freeze frame data, offering insight into the conditions that activated the code.

– Visual examination: Inspect the throttle and pedal position sensor/switch, wiring, and connectors for visible damage or corrosion.

4. Resolving Causes of DTC P0221:

Addressing DTC P0221 involves specific actions tailored to the underlying issue:

– Throttle and pedal position sensor/switch replacement: Replace the malfunctioning sensor/switch with a new unit adhering to manufacturer specifications.

– Wiring and connector repair: Repair or replace damaged wiring and connectors to ensure accurate signal transmission.

– Throttle control system inspection and repair: Ensure the throttle control system is functioning correctly.

– ECM diagnosis: If an ECM malfunction is suspected, diagnose and address the issue through reprogramming or replacement.

5. Clearing DTC P0221:

After effectively resolving the root cause, clear the DTC from the ECM’s memory using an OBD-II scanner. This step confirms the issue’s resolution and prevents the CEL from reappearing.


DTC P0221, indicating Throttle/Pedal Position Sensor/Switch “B” Circuit Range/Performance, underscores the significance of accurate sensor readings for optimal engine performance. By understanding its causes, recognizing its symptoms, employing meticulous inspection techniques, and implementing effective solutions, mechanics can accurately diagnose and rectify this issue. Ensuring precise throttle and pedal position data is pivotal for achieving improved throttle response, engine efficiency, and overall vehicle operation.