P0548 Exhaust Gas Temperature Sensor Circuit Low Bank 2 Sensor 1

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. Bank 2 sensor 1 exists only on V engines with a separate exhaust path per cylinder bank. No manufacturer document available to us uses this code; the thresholds known for bank 1 apply by analogy. P0548 means the signal is below range, usually a short to ground – for bank 1 GM uses below 142 Ω, Ford below 0.10 V.

Likely causes

Symptoms

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

Repair estimate

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

Parts involved

Related codes

References: hella.com, gsi.ext.gm.com, fordservicecontent.com, law.cornell.edu.