Powertrain
generic / SAE
P05F8
Reductant Heater Control Module Performance
The reductant heater module is electrically intact but does not deliver the expected thermal effect - heater elements aged, supply line resistance, or thermostat sensor offset.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number5 / F8
Possible causes
- Heater element aged high
- Module software outdated, reflash may resolve low
- Supply voltage outside specification 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: possible
- Estimated cost: 120–600 €
- Estimated time: 0.6–2.5 h
- Component: reductant heater control module
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012