Exhaust Gas Temperature Sensor Circuit High (Bank 2 Sensor 1)
The P0549 code indicates that the Engine Control Module (ECM) has detected a high voltage signal from the exhaust gas temperature (EGT) sensor located on Bank 2, Sensor 1 (pre-catalyst). This sensor monitors exhaust temperature to protect the catalytic converter and DPF. A high voltage reading typically means the sensor circuit has an open, short to power, or the sensor itself is faulty. This can lead to incorrect fuel trims, reduced engine performance, and potential damage to emission components if ignored.
1. Most Common Causes
- Faulty exhaust gas temperature sensor
- Open or shorted wiring in sensor circuit
- Corroded or damaged connector
- ECM software or hardware issue
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or limp mode
- Poor fuel economy
- Possible overheating of catalytic converter
3. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect EGT sensor connector and wiring for damage or corrosion.
Step 3: Measure sensor resistance and compare to specifications (typically 100-200k ohms at room temperature).
Step 4: Check for short to power or ground in the signal circuit.
Step 5: If all tests pass, replace the EGT sensor.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as it can cause catalytic converter damage or reduced performance. Short trips to a repair shop are acceptable.
How much does it cost to fix?▼
The typical repair cost ranges from $50 to $150 for a DIY sensor replacement, or $150 to $300 at a shop including labor.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.