P2041

Reductant Injection Air Pressure Sensor A Circuit Intermittent

Q: 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.

Q: 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.

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.

Real-world scan data

Seen in

scans in the past year

Found in

<0.1%

of scans

<0.1%

of scans that found faults

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

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.

Read & clear P2041 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX