P0544
Exhaust Gas Temperature Sensor Circuit - Bank 2 Sensor 1
Powertrain Emission Controls Exhaust Temperature Sensor 🟡 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 (the side opposite the #1 cylinder) isn't sending the right signal to the engine computer. It's like a broken thermometer that can't tell the engine how hot the exhaust is.

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Symptoms You May Notice
3 known symptoms for this code
Check Engine Light illuminated
Reduced fuel economy
Engine running rough or hesitant during acceleration
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Embedded Systems Insight
What the ECU/ECM is actually computing

The ECU monitors exhaust gas temperature to optimize fuel injection and emissions control. The sensor generates a voltage signal (typically 0–5V) that correlates to exhaust temperature. Faults occur when voltage is out of range, the circuit is open/shorted, or response time is too slow.

Voltage & Parameter Thresholds

Parameter Normal Range Fault Condition
Sensor Voltage 0.2–4.8V (temperature dependent) <0.1V or >5.0V
Exhaust Temperature 200–900°F (88–482°C) during operation Implausible readings or no signal
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Diagnostic & DIY Fix Guide
Check these in order — from cheapest to most complex
1
Wiring harness and connector
Inspect for corrosion, loose pins, or damaged insulation at the sensor connector and repair as needed.
2
Exhaust Gas Temperature Sensor
Unbolt the sensor from the exhaust manifold or pipe on bank 2 and install a new OEM or quality aftermarket replacement.
3
Engine Control Module (ECM) reprogramming
If wiring and sensor are good, the ECM may need reprogramming or replacement by a dealer.