Throttle Position Sensor B Circuit Range/Performance
The P0221 code indicates that the Engine Control Module (ECM) has detected a malfunction in the throttle position sensor B circuit, which is part of the electronic throttle control system. This sensor monitors the position of the throttle plate and sends a voltage signal to the ECM. The code is triggered when the signal from sensor B is out of the expected range or does not match the signal from sensor A, indicating a performance issue. Common causes include a faulty throttle position sensor, wiring issues, or a malfunctioning throttle body.
01. Most Common Causes
- Faulty throttle position sensor (TPS)
- Damaged or corroded wiring/connectors in the TPS circuit
- Carbon buildup on throttle body affecting sensor operation
- Malfunctioning throttle body assembly
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or limp mode
- Poor acceleration or hesitation
- Unstable idle or stalling
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for additional codes.
Step 2: Visually inspect the throttle position sensor wiring and connectors for damage or corrosion.
Step 3: Test the TPS voltage signal with a multimeter while manually opening the throttle; compare to manufacturer specs.
Step 4: Clean the throttle body if carbon buildup is present, then clear codes and test drive.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive with this code as it can cause sudden loss of throttle response or unintended acceleration, leading to unsafe driving conditions.
How much does it cost to fix?▼
The cost to fix P0221 typically ranges from $50 to $150 for diagnostic and cleaning, but replacement of the throttle position sensor or throttle body can cost $200-$500 or more.