Powertrain
generic / SAE
P2038
Reductant Injection Air Pressure Sensor A Circuit Range/Performance
The reductant injection air-pressure sensor A reads inside the electrical range but does not match expected behaviour over time or load — slow response or wrong offset.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number– / 38
Possible causes
- Sensor drift high
- Sensor element aged beyond calibration window low
- Sensor mounting loose - signal damping 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: 80–500 €
- Estimated time: 0.7–2 h
- Component: reductant air pressure sensor
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012