P0544Exhaust Gas Temperature Sensor Circuit Bank 1 Sensor 1
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- The exhaust gas temperature sensor is a thermistor in a voltage divider with the module's pull-up resistor; the first one (sensor 1) sits before the turbocharger, the oxidation catalyst or after it depending on the maker. Diesels use it for particulate filter regeneration and component protection; CARB names it explicitly as a monitored input. P0544 is the general fault of bank 1 sensor 1. Ford's 6.7 L diesel uses it not as a circuit fault but for plausibility against an exhaust temperature model: after at least 6 h off it compares sensor and model over 200–400 s, a fault exceeding ±80 °C for 20 s, once per trip. GM's Duramax does not use P0544. The module then runs on a model value and may restrict filter regeneration.
- What you may notice
- Check engine light on
- Particulate filter regeneration missing, filter warning
- Possible power reduction
- Likely causes
- LikelySensor aged or drifting, soot on the tip
- PossibleCable or connector damaged by heat or vibration
- RareExhaust leak before the sensor
- RareExhaust temperature really deviating (injection fault)
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €60 – €300
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.