Throttle/Pedal Position Sensor C/F Voltage Correlation
The P0229 code means the vehicle's onboard diagnostic system has detected: Throttle/Pedal Position Sensor C/F Voltage Correlation. This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- moderate
- Estimated cost
- $100 - $500 (parts and labor)
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Common Symptoms
- Check Engine Light on
- Vehicle enters reduced power mode
- Throttle response feels inconsistent
- Multiple TPS-related codes may be stored
Probable Causes (Ranked by Likelihood)
- One TPS sensor reading differently from its paired sensor Very High
- Carbon buildup on throttle blade causing sensor disagreement High
- Damaged wiring on one sensor circuit only Moderate
- PCM calibration or software fault Low
Frequently Asked Questions
What does voltage correlation mean?
The PCM compares voltage readings from multiple throttle sensors. They should agree within a calibrated tolerance. A correlation fault means they disagree beyond that tolerance.
Can this be caused by a single bad sensor?
Yes, if one sensor in a pair is drifting or has a dead spot, it will disagree with its partner sensor, triggering the correlation code.
Do I need to replace both sensors?
Not always. Diagnose which sensor is reading incorrectly by comparing all TPS readings. Replace only the faulty component.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
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Read all TPS sensor voltages simultaneously on scan tool. Compare TPS C and F readings across throttle range.
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Calculate the expected correlation between sensors. They should have a predictable mathematical relationship.
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Clean throttle body and retest. Carbon buildup can cause one sensor to read slightly different.
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If cleaning does not resolve, replace the throttle body or accelerator pedal position sensor assembly.
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
Commonly Affected Vehicles
- 2010-2020 Ford F-150 (3.5L EcoBoost)
- 2012-2019 Chevrolet Silverado (5.3L)
- 2008-2018 Ram 1500 (5.7L HEMI)
- 2011-2020 GMC Sierra (5.3L)
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