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P22A3 Powertrain

NOx Sensor Heater Control Circuit/Open (Bank 1 Sensor 2)

NOx Sensor Heater Control Circuit/Open (Bank 1 Sensor 2): the control circuit is open. The NOx sensor heater brings the sensor to operating temperature; a fault delays accurate NOx readings used for SCR control.

Affected components

  • Nox sensor

Common causes

  • High likelihood: Heater winding open
  • Low likelihood: Pin pushed back out of connector body
  • Low likelihood: Cracked solder joint inside the module or sensor

Possible symptoms

  • Check engine light or NOx warning on
  • AdBlue/DEF level or quality warning
  • Possible no-start countdown after ignore period
  • Failed emissions inspection (NOx)

Diagnostic notes

  • The malfunction indicator lamp may illuminate
  • This code can affect emissions

Related codes

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.

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