Reductant Pressure Too Low
The pressure in the DEF system is lower than expected.
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 computer monitors the pressure of the Diesel Exhaust Fluid (DEF) in the tank. If it senses low pressure, like below 10 PSI, it throws this code.
What the computer is actually seeing
The engine control module (ECM) reads the pressure sensor input from the DEF tank. It expects a pressure signal of between 10 to 150 PSI under normal operation. Anything below this range triggers the code.
What a healthy reading looks like
Normal DEF pressure is typically 10-150 PSI; low pressure will be indicated by values below 10 PSI.
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.
- 1Check the DEF fluid level. It should be above the minimum level in the tank.
- 2Inspect the DEF lines and connectors for any leaks or damage. Repair as needed.
- 3Test the pressure sensor. Disconnect it and measure resistance; it should fall within manufacturer specs (typically 1-5 ohms).
- 4Check for any wiring issues or corrosion at sensor connectors. Clean or replace as necessary.
- 5If all else checks out, replace the pressure sensor.
Common causes
- DEF tank is empty or very low
- Leaking DEF lines or fittings
- Faulty pressure sensor
- Corroded or loose electrical connections
- Blocked or contaminated DEF filter
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's drivable but you may notice reduced engine performance or emissions issues. It's best to fix it soon.
Will this code come back after clearing it?
If the underlying issue isn't fixed, the code will likely return.
Why does this code pair with other codes?
This code is often related to DEF system issues, and multiple faults can stem from similar problems like low DEF or sensor failures.
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