P0223

What it means

P0223 means the engine control unit has seen the signal voltage from throttle or pedal position sensor B sitting higher than the expected range. Sensor B is the second, redundant track used to cross-check the main throttle or pedal signal. The fault is usually set when the circuit reads close to reference voltage, or when the two tracks disagree and B is judged to be too high.

Symptoms

• Engine warning light on
• Car goes into limp mode with reduced power
• Poor or delayed throttle response
• Unstable or high idle
• Engine hesitation or surging when pulling away
• Cruise control not working

Possible causes

• Faulty throttle body or throttle position sensor track B (internal fault or worn track)likely
• Faulty accelerator pedal position sensor track B, depending on which sensor the vehicle assigns as Blikely
• Signal wire shorted to the sensor supply voltage or to another live circuitpossible
• Open circuit or high resistance in the sensor earth return, which pushes the signal reading highpossible
• Corroded, damaged or loose connector terminals at the sensor or control unitpossible
• Dirty or sticking throttle body causing implausible readings and setting a related faultrare
• Faulty engine control unitrare

How to diagnose

1. Read all stored and pending codes and record the freeze frame data, noting engine speed, load and throttle angle when the code set. Check for other throttle, pedal or reference voltage codes.
2. Look up which sensor is designated B on this model and engine, as it may be the throttle body or the pedal.
3. Inspect the wiring and connectors for the identified sensor for chafing, water ingress, bent or pushed-back pins and corrosion.
4. With live data, compare sensor A and sensor B readings at rest and while slowly moving the pedal. Look for B reading high at rest, or a jump or flat spot in the sweep.
5. Check the sensor reference supply and earth at the connector against the manufacturer's specification.
6. Test the signal wire for a short to supply or another circuit, and test the earth for continuity and resistance, with the ignition off and the control unit disconnected where specified.
7. Check the throttle body for heavy carbon build-up and smooth movement of the plate, if it is the throttle sensor.
8. If wiring and sensor are proven good, check for software updates or control unit faults following the manufacturer's procedure.

How to fix

• Replace the faulty throttle body or pedal assembly, as the sensor is often not supplied separately.
• Repair any shorted, open or high resistance wiring, including the earth return.
• Clean or replace corroded connector terminals and secure the connector.
• Clean the throttle body using the correct method for the model, and then carry out any throttle adaption or relearn procedure required.
• Repair or replace the control unit only when all other causes have been ruled out, and then code or programme it as required.

Can I keep driving?

Nearby codes

• P0222GenericThrottle/Pedal Position Sensor/Switch B Circuit Low
• P0224GenericThrottle/Pedal Position Sensor/Switch B Circuit Intermittent