P0548: Exhaust gas temperature sensor, bank 2 sensor 1 — electrical input low — what it means, the affected system and what to check before replacing parts.
Meaning, symptoms, causes and checks
The monitor for exhaust gas temperature sensor, bank 2 sensor 1 detects an electrical value below the allowed range; this does not by itself mean that speed, pressure or temperature is physically low. Bank and sensor numbers identify the monitored channel, not a universal physical mounting location. Electrical signal level must not be confused with actual exhaust temperature.
Affected system: Exhaust gas temperature sensing
Symptoms
- Warning light may illuminate
- Related system function may be impaired
- Vehicle-specific symptoms vary
Possible causes
- Exhaust or emissions plumbing leak, restriction, valve fault, sensor fault, or damaged wiring
- Related wiring, connector, power or ground fault
- Vehicle-specific mechanical or control issue
What to check
- Record stored and pending codes and freeze-frame data
- Inspect the relevant exhaust or emissions plumbing and electrical connections, then compare commanded operation with sensor feedback during the enable conditions.
- Confirm measured values against the vehicle service information
- Retest under the conditions that set the code
- Inspect the relevant exhaust or emissions plumbing and electrical connections, then compare commanded operation with sensor feedback during the enable conditions.
- Repair the verified cause and confirm the code does not return
Also written as: P0548-00, P054800, PO548 (some scan tools add the fault-type byte, e.g. -00).