Powertrain, generic · Vehicle speed, idle control and auxiliary inputs

P0544 Exhaust Gas Temperature Sensor Circuit Bank 1 Sensor 1

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

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.

Likely causes

Sensor aged or drifting, soot on the tip
Cable or connector damaged by heat or vibration
Exhaust leak before the sensor
Exhaust temperature really deviating (injection fault)

Symptoms

  • Check engine light on
  • Particulate filter regeneration missing, filter warning
  • Possible power reduction

Repair estimate

DifficultyMediumDIY possible
Parts and labour€60–300
Time0.5–1.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

exhaust gas temperature sensorsensor wiringengine control module

Related codes

P0545P0546P2080P2081P0547P2031

References: fordservicecontent.com, hella.com, law.cornell.edu.