Exhaust Gas Temperature Sensor Circuit Low (Bank 2 Sensor 1)
The P0548 code means the vehicle's onboard diagnostic system has detected: Exhaust Gas Temperature Sensor Circuit Low (Bank 2 Sensor 1). This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- moderate
- Estimated cost
- $100 - $400 (parts and labor)
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What Are the Symptoms of P0548?
- Check Engine Light on
- Bank 2 DPF regeneration issues
- Reduced power
- Exhaust system management limited
What Causes P0548? (Most Likely First)
- Short to ground in Bank 2 EGT sensor wiring Very High
- Failed Bank 2 EGT sensor with internal short High
- Moisture in Bank 2 EGT sensor connector Moderate
- Wiring damage near Bank 2 exhaust manifold Moderate
Can I Still Drive with P0548?
Short distances only. P0548 is rated moderate severity. Keep trips short and get it diagnosed soon rather than waiting for symptoms to worsen.
Frequently Asked Questions
Is P0548 diagnosis the same as P0545?
The diagnostic approach is the same but focused on the Bank 2 side. Check the Bank 2 EGT sensor, its wiring, and connector. The root causes are identical; only the location differs.
Can exhaust leaks affect EGT sensor readings?
Yes. An exhaust leak before the EGT sensor location can introduce cooler ambient air, causing lower temperature readings. However, a circuit low code typically indicates an electrical issue rather than an actual temperature change.
How hot do exhaust gas temperatures get?
Normal exhaust gas temperatures range from 400F to 1200F depending on engine load and type. During DPF regeneration on diesels, temperatures can reach 1100F to 1400F. EGT sensors must withstand these extreme conditions.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose P0548?
-
Compare Bank 2 EGT reading to Bank 1; a much lower Bank 2 reading confirms the circuit issue
-
Disconnect the Bank 2 EGT sensor and check for short to ground on the signal wire
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Inspect the Bank 2 sensor connector for moisture or corrosion
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Measure Bank 2 sensor resistance and compare to Bank 1 sensor
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
Which Vehicles Commonly Get P0548?
- 2007-2017 GMC Sierra 6.6L Duramax
- 2008-2018 Ford F-350 6.7L Powerstroke
- 2010-2020 Ram 3500 6.7L Cummins
- 2009-2019 Audi Q7 TDI
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