Throttle Position Sensor B/Accelerator Pedal Correlation (Toyota)
What does P1224 mean?
The P1224 code means the vehicle's onboard diagnostic system has detected: Throttle Position Sensor B/Accelerator Pedal Correlation (Toyota). This is a moderate severity code.
Common Symptoms
- Check Engine Light on
- Reduced engine power or limp mode
- Sluggish throttle response
- Vehicle may limit RPM
- Intermittent loss of acceleration
Probable Causes (Ranked by Likelihood)
- Faulty throttle body with worn dual TPS Very High
- Worn accelerator pedal position sensor High
- Wiring issue between APP sensor and throttle body Moderate
- Carbon buildup affecting throttle plate movement Moderate
- ECM calibration or software issue Low
Step-by-Step Diagnostic Procedure
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Compare TPS and APP sensor readings on a scan tool during pedal sweep
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Check that throttle opening matches accelerator pedal position
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Clean the throttle body to remove carbon deposits
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Inspect all connectors on the throttle body and pedal assembly
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Replace the throttle body or pedal assembly if sensors show wear
Frequently Asked Questions
What is TPS/APP correlation?
The ECM compares the accelerator pedal position with the actual throttle body position. They should match within a tolerance. If the throttle is not following the pedal accurately, a correlation fault is set.
Was this related to the Toyota recall?
Toyota issued recalls for some models related to electronic throttle control concerns. Check with your Toyota dealer using your VIN to see if any open recalls apply to your vehicle.
Can throttle body cleaning fix P1224?
In some cases, carbon buildup prevents the throttle plate from moving freely, which causes the throttle position to lag behind the pedal position. Cleaning can help, but if the sensors are worn, replacement is needed.