Throttle/Pedal Position Sensor B Circuit High
In short
P0223 means the engine computer (PCM) detected a higher-than-expected voltage on the 'B' signal circuit of the throttle position or accelerator pedal position sensor. Because modern drive-by-wire vehicles use two sensor signals for safety cross-checking, this usually points to a problem on one of the redundant circuits. The most common real-world cause is wiring trouble — a chafed harness, corroded connector, or open circuit — rather than the sensor itself, though a failed throttle body or pedal assembly is also frequent.
Is it safe to drive with P0223?
It is generally safe to drive a short distance, but most vehicles enter a reduced-power 'limp' mode that limits throttle response and speed, which can be hazardous when merging or climbing hills. The engine may also stall or hesitate unexpectedly. Have it diagnosed before relying on the car for highway or commuting use.
Symptoms
- Illuminated check engine light, often with a separate throttle/wrench warning light
- Reduced engine power or 'limp home' mode with capped RPM and speed
- Hesitation, surging, or lack of response when pressing the accelerator
- Rough or unstable idle, occasionally stalling
- Poor acceleration and noticeably sluggish throttle pedal feel
- Hard starting or the engine refusing to rev past a set limit
Common causes (most → least likely)
How to diagnose it (before buying parts)
- 1 Scan and record all stored codes and freeze-frame data; note whether P0223 appears alone or alongside other throttle/pedal codes (P0123, P0222, P2135, etc.), which helps point to throttle body vs. pedal.
- 2 Visually inspect the throttle body and accelerator pedal connectors and harness for corrosion, chafing, melted insulation, bent pins, or loose terminals; wiggle-test the harness while watching live data for signal dropouts.
- 3 With the key on and engine off, use a scan tool to view the TPS-B and APP-B voltage in live data and watch it sweep smoothly as the pedal is pressed; a reading stuck high or pinned to reference voltage confirms the fault is live.
- 4 Back-probe the sensor connector with a multimeter to verify the 5V reference and ground are present and within spec, then check the signal wire for a short to voltage or an open compared to the wiring diagram.
- 5 Clear the code and recheck; if it returns, isolate between the sensor and the harness by testing continuity end-to-end and confirming the PCM-side circuit before condemning any part.
Repair options & cost
By manufacturer
GM trucks and SUVs are known for electronic throttle body and APP sensor faults; cleaning rarely fixes electrical 'B' circuit issues, and a throttle relearn idle procedure is often needed after replacement.
On Ford vehicles, pedal-side APP sensor faults and chafed harness sections near the throttle body are common; check for technical service bulletins covering reduced-power events.
VAG vehicles commonly throw throttle/pedal 'B' circuit codes from connector corrosion and pedal module failures, frequently triggering the EPC (Electronic Power Control) warning light alongside reduced power.
Nissan applications are prone to electronic throttle body failures; an accelerator-pedal and throttle relearn (idle air volume learning) is often required after repairs to clear the fault.
Frequently asked questions
Can I drive with a P0223 code?
You can drive short distances, but the vehicle will likely be in reduced-power limp mode with limited acceleration, which is unsafe for highway merging or hills. Get it diagnosed quickly, and avoid relying on the car for demanding driving until the throttle circuit is repaired.
Is P0223 the throttle body or the gas pedal?
It can be either, since both share redundant 'B' signal circuits. Look at companion codes and use live data: if the throttle-side signal is abnormal it points to the throttle body, while a stuck pedal-side reading points to the accelerator pedal sensor. Confirm with wiring tests before buying parts.
Will cleaning the throttle body fix P0223?
Usually not. P0223 is an electrical circuit fault (signal reading too high), not a carbon-buildup or airflow problem. Cleaning may help unrelated idle issues, but the real fix is repairing wiring, connectors, or replacing the failed sensor.
Do I need a throttle relearn after fixing P0223?
Often yes. Many vehicles require a throttle-body or accelerator-pedal relearn procedure after replacing the sensor or disconnecting the battery so the PCM can re-establish the idle and pedal range. A capable scan tool can perform this; some vehicles relearn through a key-cycle sequence.