P2041
Reductant Injection Air Pressure Sensor A Circuit Intermittent
Auxiliary emissions (SCR/reductant)
Generic OBD-II
Medium
What it means
P2041 means the signal from reductant injection air pressure sensor 'A' is dropping out intermittently. On diesel SCR systems this sensor helps meter DEF (reductant) into the exhaust, so the fault is about emissions control rather than how the engine drives. It usually traces to a loose connector or chafed wiring, and if left unfixed can eventually trigger a power derate.
Medium
Can I keep driving? Drivable in the short term, but diesel SCR faults can trigger a speed/power derate if left unrepaired; get it fixed to stay legal and avoid limp mode.
Common symptoms
What you'll notice
- Check-engine light on (sometimes an emissions/DEF warning)
- Intermittent SCR or exhaust-treatment warning messages
- Possible reduced-power/derate warning if the fault persists (diesel)
- Often no change in how the engine feels day to day
Common causes
Most likely first
- Loose or intermittent connector at the reductant air pressure sensorLikely
- Chafed, pinched, or corroded wiring in the sensor circuitCommon
- Failing reductant injection air pressure sensor 'A'Common
- Poor ground or supply to the sensorLess often
- Faulty ECM/PCM or SCR control moduleLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data to see when the intermittent signal occurred.
- Inspect and wiggle-test the sensor connector and harness for intermittent opens, corrosion, or chafing; repair as needed.
- Verify the sensor's ground and reference voltage are steady.
- Test the reductant air pressure sensor per the service manual and replace it if the signal drops out.
- Clear the code and road-test, watching live data for signal glitches.
FAQ
Quick answers
Is it safe to drive with P2041?+
You can usually drive short-term, but SCR faults on diesels can escalate to a power/speed derate. Repair it promptly to avoid limp mode and stay emissions-legal.
Can I just clear P2041?+
An intermittent fault may stay clear briefly, but it returns once the glitch reoccurs, so the wiring or sensor should be repaired.
Related codes
Often seen with P2041
Read & clear P2041 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX