Reductant Reservoir Heater "A" Control Circuit
A general electrical fault on the reductant tank heater "A" control circuit. AdBlue freezes at -11 C, so the tank heater must work for cold-start dosing.
Affected components
- Reductant tank heater
- Reductant heater wiring
Common causes
- High likelihood: Heater element failed
- Medium likelihood: Wiring open or connector loose
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
- 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.