P0222: Throttle/Pedal Position Sensor B Circuit Low Input
The P0222 code indicates that the Engine Control Module (ECM) has detected a low voltage signal from the throttle position sensor (TPS) or accelerator pedal position sensor (APP) circuit B. This sensor is typically a potentiometer that provides a variable voltage signal based on throttle plate or pedal position. A low input means the voltage is below the expected range (usually below 0.5V), which can be caused by a short to ground, open circuit, faulty sensor, or wiring issues. This code often triggers the check engine light and may cause reduced engine power or limp mode.
1. Most Common Causes
- Faulty throttle position sensor (TPS) or accelerator pedal position (APP) sensor
- Signal wire for circuit B shorted to ground
- Open circuit in the 5V reference voltage or sensor ground
- Damaged, corroded, or loose connector terminals
- Internal PCM failure (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or limp mode
- Poor acceleration or hesitation
- Engine stalling or rough idle
- Unresponsive throttle pedal
3. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm code P0222 and check for other related codes.
Step 2: Visually inspect the TPS/APP sensor wiring and connectors for damage, corrosion, or loose connections.
Step 3: Measure voltage at the sensor signal wire with key on, engine off; should be around 0.5-1.0V at closed throttle and increase smoothly to ~4.5V at wide open throttle.
Step 4: Check for a short to ground by disconnecting the sensor and measuring resistance between signal wire and ground; should be infinite.
Step 5: If wiring and voltage are normal, replace the TPS or APP sensor and clear the code.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. The vehicle may enter limp mode, limiting speed and acceleration, which can be dangerous in traffic. Have it diagnosed and repaired promptly.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for parts and labor, depending on the vehicle and 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.