P0546
Exhaust Gas Temperature Sensor Circuit High - Bank 2 Sensor 1
Powertrain Emission Controls EGT Sensor Circuit 🟡 Moderate — Fix within a week
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What This Actually Means
In plain language — no jargon

The exhaust temperature sensor on Bank 2 is reading too hot or sending an abnormally high voltage signal to the engine computer. Think of it like a thermometer that's stuck on a high reading even when it shouldn't be that hot.

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Symptoms You May Notice
3 known symptoms for this code
Check Engine Light illuminated
Reduced engine performance or limp mode activation
Possible rotten egg smell from exhaust
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Embedded Systems Insight
What the ECU/ECM is actually computing

The ECU monitors the exhaust gas temperature (EGT) sensor voltage on Bank 2 Cylinder 1 to track post-catalyst temperatures and catalyst efficiency. When the sensor voltage exceeds the maximum expected threshold (typically 4.5-5.0V), the ECU triggers a fault indicating either a failed sensor, wiring short, or genuinely excessive exhaust temps.

Voltage & Parameter Thresholds

Parameter Normal Range Fault Condition
EGT Sensor Voltage 0.2 - 4.5V (approximately 200-800°C) > 4.5V (sensor circuit high)
Exhaust Gas Temperature 200 - 800°C post-catalyst > 900°C or sensor malfunction
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Diagnostic & DIY Fix Guide
Check these in order — from cheapest to most complex
1
Wiring and connectors
Inspect the EGT sensor wiring harness for corrosion, damage, or loose connectors and repair or reseat as needed.
2
Exhaust Gas Temperature Sensor
Remove and replace the faulty EGT sensor on Bank 2 with an OEM or quality aftermarket unit.
3
Engine Control Module (ECM) software
Update or reflash the ECM if wiring and sensor are confirmed good, as software corruption can cause false readings.