P0548 Exhaust Gas Temperature Sensor Circuit Low Bank 2 Sensor 1

P0548 points to a low signal from Exhaust Gas Temperature Sensor Bank 2 Sensor 1. The upstream Bank 2 EGT reading is below the expected range.

Code status

Needs verification

Not yet verified against SAE J2012_202509 / J2012DA. Treat unverified rows as a lookup aid, not repair authority.

System: Speed / Idle
Scope: iso-sae-controlled-p0
Standard: SAE J2012 / ISO 15031-6
Source: legacy-import

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not replace exhaust hardware before testing the low EGT signal and wiring near Bank 2.

Useful checks before replacing parts

Check Bank 2 Sensor 1 EGT signal voltage, bias or reference circuit, ground, cold-start reading, engine load, and freeze-frame data.
Inspect for short-to-ground faults, open bias circuits, exhaust-heat damaged wiring, connector corrosion, and failed sensor elements.
Compare Bank 2 readings to ambient and Bank 1 behavior to determine whether the fault is electrical or thermal.

Related OBD-II codes

These nearby speed / idle entries can help compare wording and fault area. They may share the same verification status as the source database.