Reductant Injection Air Pressure Sensor Circuit Range/Performance
The P2038 code means the vehicle's onboard diagnostic system has detected: Reductant Injection Air Pressure Sensor Circuit Range/Performance. This is a serious severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- hard
- Estimated cost
- $200 - $600 (parts and labor)
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What Are the Symptoms of P2038?
- Check Engine Light illuminated
- DEF system warning message
- Reduced engine power
- SCR efficiency below threshold
- Countdown timer to speed limitation on some vehicles
What Causes P2038? (Most Likely First)
- Degraded air pressure sensor reading out of range Very High
- Partially blocked air supply line High
- Leaking air supply connections Moderate
- Contaminated sensor Moderate
- PCM calibration issue Low
Can I Still Drive with P2038?
Short distances only. P2038 is rated serious severity. Keep trips short and get it diagnosed soon rather than waiting for symptoms to worsen.
Frequently Asked Questions
What does P2038 mean?
P2038 means the reductant injection air pressure sensor is reporting values outside the expected operating range, indicating the DEF injection system is not receiving correct air pressure data.
Can I drive with a P2038 code?
Short-distance driving is possible, but some vehicles may impose a speed limiter countdown if the DEF system is not functioning properly.
How much does it cost to fix P2038?
Expect $200 to $600 for sensor replacement or air line repair.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose P2038?
-
Read freeze frame data and confirm P2038
-
Monitor air pressure sensor readings under different engine loads
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Inspect air supply lines for leaks or partial blockages
-
Compare sensor reading to a reference pressure gauge
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
Which Vehicles Commonly Get P2038?
- 2013-2020 Ram 2500 6.7L Cummins
- 2011-2019 Chevrolet Silverado 2500 6.6L Duramax
- 2009-2015 Volkswagen Jetta 2.0L TDI
- 2012-2018 BMW 328d 2.0L Diesel
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