Powertrain
generic / SAE
P24FF
Reductant Temperature Too High
The temperature of the AdBlue/DEF in the dosing system exceeds the safe limit — risk of thermal decomposition (NH3/biuret formation) and clogged dosing nozzles. Often caused by a stuck-on tank heater, a stalled coolant return or proximity to a hot exhaust component.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number4 / FF
Possible causes
- Tank heater stuck on high
- Heat soak from exhaust or engine bay 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: 200–1200 €
- Estimated time: 0.6–3 h
- Component: reductant tank
- Component: reductant tank heater
- Component: reductant lines
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012