Powertrain
generic / SAE
P209F
Reductant Tank Heater Control Circuit Performance
DEF tank heater is electrically OK but does not warm the tank within the expected time — element is partially open, fluid level too low for proper heat transfer, or the heater is undersized for the ambient temperature.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number– / 9F
Possible causes
- Heater element partially open high
- DEF level too low for heat transfer medium
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: 80–700 €
- Estimated time: 0.7–2.5 h
- Component: reductant tank heater
- Component: reductant temperature sensor
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012