Exhaust Gas Temperature Sensor Circuit High - Bank 2 Sensor 1
The exhaust temperature sensor on Bank 2 is sending a voltage signal that's too high, like a thermometer reading impossibly hot. The engine computer thinks the exhaust is overheating when it may actually be fine or the sensor itself is faulty.
The ECU monitors the EGT sensor voltage to ensure exhaust temperatures stay within safe operating range. When voltage exceeds the maximum threshold, the ECU sets a fault code. The sensor operates on a linear voltage scale where higher voltage indicates higher temperature.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| EGT Sensor Voltage (Bank 2 Sensor 1) | 0.5–4.5 volts (temperature-dependent) | >4.8 volts or open circuit detected |
| Exhaust Gas Temperature | 200–900°C under normal operation | >950°C or sensor signal implausible |
Code P0549 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, P0549 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.