Powertrain
generic / SAE
P20EC
Reductant Heater "A" Control Stuck Off
The reductant tank heater "A" does not heat when commanded on. Either a failed element or a stuck-off driver in the dosing module.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number– / EC
Possible causes
- Heater element open high
- Heater driver stuck off medium
- Carbon or debris buildup preventing free movement low
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)
Inspection / repair
- Difficulty: medium
- DIY: shop recommended
- Estimated cost: 200–1200 €
- Estimated time: 1–4 h
- Component: reductant tank heater
- Component: reductant dosing unit
- MIL / check engine light
- emissions-relevant
- drive cycle required
Sources
References
sae:J2012