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

P0546 Exhaust Gas Temperature Sensor Circuit High 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. P0546 means the signal is above range: GM L5P above 922 Ω, GM LML above 2.21 V, Ford 6.7 L above 2.66 V for about 2 s, Saab 9-5 2.0 TiD above 4.9 V for 1 s. Most often an open circuit pulled up to the reference, otherwise a short to positive; live data then show −40 °C or the maximum. The module uses a substitute value and blocks filter regeneration.

Likely causes

Sensor element or internal lead open (vibration, heat)
Connector loose or corroded, broken wire
Signal line shorted to positive
Engine module

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

P0544P0545P2080P2081P0549P2033

References: fordservicecontent.com, gsi.ext.gm.com, gsi.ext.gm.com, saabwisonline.com.