Intake Air O2 Sensor Heater Control Circuit Low Bank 1
Voltage on the intake air O2 sensor heater control line on bank 1 is below the expected window. Wire shorted to ground or heater element shorted.
Affected components
- Intake air o2 sensor b1
- Intake air o2 sensor heater b1
- Wiring harness
- Ecm
Common causes
- High likelihood: Heater wire shorted to ground
- Medium likelihood: Heater element shorted
- Low likelihood: Connector pins corroded - high contact resistance
Possible symptoms
- Check engine light on after several drive cycles
- Slightly increased fuel consumption during cold start
- Delayed entry into closed-loop fuel control
- Failed emissions inspection (lambda readiness)
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- A drive cycle may be required after repair
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.