Throttle Position Sensor Output Circuit Open
The P2620 code indicates that the Engine Control Module (ECM) has detected an open circuit in the throttle position sensor output circuit. This sensor monitors the throttle plate angle and sends a voltage signal to the ECM. An open circuit means there is a break in the wiring or a faulty sensor, preventing the signal from reaching the ECM. This can lead to incorrect air-fuel mixture, poor engine performance, and potential limp mode activation.
1. Most Common Causes
- Open or high resistance in the TPS signal, reference, or ground circuit
- Corroded, disconnected, or damaged pins in the throttle position sensor connector
- Internally defective throttle position sensor (TPS)
- Intermittent or permanent short circuit in the TPS output circuit wiring
- Internal PCM failure in the throttle signal processing circuit
- Faulty electronic throttle body (when the TPS is an integrated non-serviceable component)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Poor acceleration or hesitation
- Engine stalling or rough idle
- Reduced fuel economy
3. Step-by-Step Diagnosis
Step 1: Connect an OBD2 scanner and confirm code P2620. Check for other related codes.
Step 2: Visually inspect the throttle position sensor wiring and connector for damage, corrosion, or loose connections.
Step 3: Using a multimeter, test the sensor's reference voltage (typically 5V) and ground at the connector.
Step 4: Measure the sensor output signal voltage while manually moving the throttle plate; it should vary smoothly between 0.5V and 4.5V.
Step 5: If signal is missing or erratic, replace the throttle position sensor. If wiring is damaged, repair or replace the harness.
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. Additionally, poor engine performance may cause stalling.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for parts and labor. A new throttle position sensor costs around $20-$60, and labor is about $30-$90 depending on the vehicle.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.