Reductant Pressure Too Low
The reductant pressure is below the expected threshold.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The engine's control unit expects a certain pressure from the urea (DEF) pump for the emissions system, and it’s not getting it.
What the computer is actually seeing
The engine control module (ECM) detects that the pressure reading from the reductant pressure sensor is lower than the preset minimum, usually around 10 PSI during operation.
What a healthy reading looks like
Reductant pressure should typically be between 10-30 PSI when the system is active.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check the DEF level in the tank; should be above the minimum level indicated by the gauge. If low, refill and retest.
- 22. Inspect the wiring and connectors to the reductant pressure sensor; look for damage or corrosion. Repair as necessary.
- 33. Measure the actual pressure from the reductant pump and compare it to expected values (10-30 PSI). If it’s low, suspect the pump.
- 44. Check for any blockages or leaks in the DEF delivery system. Make sure lines are clear and not frozen if cold.
- 55. If all previous checks are normal, replace the reductant pressure sensor.
Common causes
- Faulty reductant pressure sensor
- Low DEF level
- Blocked or damaged DEF lines
- Faulty DEF pump
- Electrical issues in wiring or connectors
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
Yes, but it can lead to reduced engine performance and increased emissions. Fix it soon.
Will the code come back if I clear it?
Possibly, if the underlying issue isn't resolved the code will likely return.
Why does this code pair with other codes?
It often indicates multiple potential issues within the DEF system, so symptoms may overlap.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
Start guided diagnostic →