P0223

Throttle/Petal Position Sensor/Switch B Circuit Low Input

Powertrain Speed/Idle Control Throttle sensor signal 🟡 Moderate — Fix within a week ⚠️ Drive with Care
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What This Actually Means

In plain language — no jargon

The engine computer detected that the throttle pedal sensor is sending a voltage signal that's too low, similar to a dimmer switch stuck at the lowest setting. This tells the ECU the throttle isn't opening properly, even though the driver may be pressing the pedal.

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Symptoms You May Notice

3 known symptoms for this code
Check Engine Light illuminated
Reduced engine power or limp mode engagement
Difficulty accelerating or unresponsive throttle
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How Your ECU Detects This

Technical sensor logic and voltage thresholds

The ECU monitors voltage output from the throttle position sensor (typically 0.5–4.5V for normal operation). When voltage drops below the minimum expected threshold, the computer triggers this fault code and may default to safe limp-home mode. The ECU compares actual sensor voltage against stored calibration curves to detect out-of-range conditions.

Voltage & Parameter Thresholds

ParameterNormal RangeFault Condition
Sensor Voltage 0.5–4.5V Below 0.5V or open circuit
Pedal Position Signal 5–95% range Below 5% (low input)
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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex
1
Throttle pedal connector
Inspect and reseat the connector at the pedal sensor; corrosion or loose pins often cause low voltage signals.
2
Throttle position sensor wiring harness
Check for damaged, pinched, or corroded wires between the sensor and ECU; repair or replace as needed.
3
Throttle position sensor
If voltage remains low after wiring checks, replace the sensor itself as it may be failing internally.
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When to See a Professional Mechanic

Not all fault codes are safe to DIY

Code P0223 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.

Safety note: OBD-II codes identify the system or circuit where a fault was detected — they do not always identify the exact failed component. A professional mechanic using live sensor data will diagnose the root cause more accurately than replacing parts based on the code alone.
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How to Clear Code P0223

What happens after you fix the fault

Once the fault is repaired, P0223 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.

The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.

✅ Safe to Clear When
  • Fault has been diagnosed and repaired
  • You want to confirm the repair worked
  • Code appeared after a sensor was cleaned
⚠️ Do Not Clear When
  • Preparing for an emissions/PUC test
  • Root cause is still undiagnosed
  • Check engine light is flashing
Emissions test note: Clearing codes resets OBD readiness monitors. Most vehicles need 50–100 km of mixed driving before monitors complete. Do not clear codes immediately before an emissions or PUC inspection.