P0548
UniversalExhaust Gas Temperature Sensor Circuit Low - Bank 2 Sensor 1
The engine computer has detected a low electrical signal in the circuit for the exhaust gas temperature sensor identified as Bank 2 Sensor 1. This sensor reports exhaust temperature so the computer can monitor and manage engine or emissions-related operation. A low circuit signal does not by itself prove that the exhaust is too cool or that the sensor has failed; wiring, connections, or the sensor may be involved. Exact sensor location and control functions depend on the vehicle.
⚠️ Before You Begin (Safety First)
The code alone does not necessarily mean the vehicle is unsafe to drive, but have it diagnosed soon because inaccurate temperature information can affect engine or emissions control. Exhaust components can remain dangerously hot after the engine is turned off; let them cool before inspecting nearby wiring. Stop driving and seek help if there is smoke, a burning smell, overheating, or a serious loss of power.
Common Symptoms
- The check-engine light may be on because the computer detected a low signal in the sensor circuit.
- There may be no noticeable change in how the vehicle runs.
- If the inaccurate temperature input affects engine or emissions management, the vehicle may show altered performance or an emissions-related warning; effects vary by vehicle.
Common Causes
- A damaged or internally faulty exhaust gas temperature sensor may produce a low circuit signal.
- Wiring may be damaged, corroded, or shorted to ground, pulling the signal low.
- A loose, corroded, or damaged connector may interrupt or distort the sensor signal.
- Heat or vibration near the exhaust may damage the sensor wiring or connector.
- A control-module or circuit fault is possible, but should be considered only after the sensor, connector, and wiring are tested.
Diagnostic Steps
- Record the code and any related codes with a scan tool before clearing them; related information can help guide diagnosis.
- With the engine off and the exhaust fully cool, visually inspect accessible wiring and connectors for looseness, corrosion, chafing, or heat damage.
- Check that the connector is seated and that its exterior is clean and undamaged; do not pull on the wires or touch hot exhaust parts.
- If the warning returns or wiring damage is found, arrange diagnosis using service information for the exact vehicle rather than replacing parts based on the code alone.
When to Call a Professional
A technician can review related codes and scan data, inspect the sensor circuit and connector, and test the wiring and sensor against model-, year-, and engine-specific service information. Confirm the circuit fault before replacing the sensor; consider a control-module fault only after the sensor and wiring have been checked.
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Commonly Asked Questions
Does P0548 mean the exhaust temperature is actually too low?
Not necessarily. It indicates a low electrical signal in the Bank 2 Sensor 1 circuit; the code alone does not establish the actual exhaust temperature.
Does this code prove the temperature sensor needs replacement?
No. A sensor, connector, damaged wiring, or another circuit fault can cause a low signal. Testing is needed to identify the cause.
Can I keep driving with P0548?
The code alone does not always require stopping immediately, but prompt diagnosis is sensible. Stop and seek help if the vehicle has smoke, a burning smell, overheating, or serious power loss.
Where is Bank 2 Sensor 1 located?
Its exact location depends on the engine and vehicle. Use vehicle-specific service information to identify the correct bank and sensor before inspecting or replacing anything.
Browse Available Code Guides
Previous and next available guides in database record order, across makes. Adjacent entries may share a code number and do not necessarily describe related faults.