P0228: Throttle/Pedal Position Sensor C Circuit High Input
The P0228 code indicates that the Engine Control Module (ECM) has detected a voltage signal from the throttle/pedal position sensor 'C' circuit that is higher than the expected range. This sensor is part of the electronic throttle control system and provides input to the ECM to determine driver demand. A high input typically means the signal voltage is above the normal operating range, which can be caused by a faulty sensor, wiring issues, or a malfunctioning ECM.
1. Most Common Causes
- Faulty throttle/pedal position sensor C
- Short to voltage in the sensor circuit
- Open or high resistance in the sensor ground circuit
- Corroded or damaged wiring/connectors
- Faulty ECM (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or limp mode
- Poor acceleration or hesitation
- Erratic throttle response
- Engine stalling or surging
3. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for additional codes.
Step 2: Visually inspect the throttle/pedal position sensor wiring and connectors for damage, corrosion, or loose connections.
Step 3: Test the sensor's reference voltage (typically 5V) and ground circuits using a multimeter.
Step 4: Measure the sensor signal voltage at idle and wide-open throttle; compare to manufacturer specifications.
Step 5: If sensor and wiring are okay, test the ECM by checking for proper output signals or perform a relearn procedure.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive with this code as it can cause reduced engine power, stalling, or unresponsive throttle, leading to unsafe driving conditions.
How much does it cost to fix?▼
The cost to fix P0228 typically ranges from $50 to $150 for parts and labor, depending on whether the sensor or wiring needs replacement.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.