The P0548: Exhaust Gas Temperature Sensor Circuit Low (Bank 2 Sensor 1) code indicates that the engine control module (ECM) has detected low voltage from the exhaust gas temperature sensor in Bank 2, Sensor 1. This sensor monitors exhaust gas temperatures to ensure proper engine performance and emissions control. Low voltage could result in incorrect readings, leading to performance and emissions issues.
P0548 – Quick Overview
| Code | Information |
|---|---|
| Meaning | P0548: Exhaust Gas Temperature Sensor Circuit Low (Bank 2 Sensor 1) |
| Is it serious? | Yes, it can affect engine performance and emissions control. |
| Possible causes | – Faulty exhaust gas temperature sensor – Low voltage to sensor – Wiring issue |
| How to diagnose? | – Test the exhaust gas temperature sensor for voltage – Inspect wiring and connectors – Check the exhaust system for issues |
P0548 Meaning
The P0548: Exhaust Gas Temperature Sensor Circuit Low (Bank 2 Sensor 1) code is triggered when the ECM detects that the voltage from the exhaust gas temperature sensor is lower than expected. This sensor plays a critical role in monitoring and controlling exhaust temperatures to protect the engine and exhaust components, as well as managing emissions. Low voltage in this circuit can result in inaccurate temperature readings, potentially leading to overheating or damage.
Step-by-step diagnostic guide
| Action | Description | Tools Needed |
|---|---|---|
| Check for Other Codes | Use an OBD-II scanner to check for related fault codes that may provide more context about the exhaust system issue. | OBD-II Scanner |
| Test the Exhaust Gas Temperature Sensor for Voltage | Use a multimeter to test the voltage output from the exhaust gas temperature sensor and ensure it matches manufacturer specifications. | Multimeter, Diagnostic Tool |
| Inspect Wiring and Connectors | Visually inspect the wiring and connectors leading to the exhaust gas temperature sensor for damage, corrosion, or loose connections. | Flashlight, Multimeter |
| Check the Exhaust System for Issues | Inspect the exhaust system components, such as the catalytic converter or exhaust manifold, for any blockages, damage, or overheating issues. | Basic Tools, Inspection Mirror |
| Clear the Code and Test Drive | After repairs, clear the code using an OBD-II scanner and test drive the vehicle to ensure proper sensor function. | OBD-II Scanner, Vehicle Manual |
| Recheck for Codes | Re-scan the vehicle after the test drive to ensure the P0548 code hasn’t returned. | OBD-II Scanner |
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