Reductant Pressure Too High
The system detected that the urea pressure is above the threshold limit.
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What it means (plain English)
The urea injection system, part of the diesel emissions controls, is seeing a pressure that's too high, which can cause it to malfunction.
What the computer is actually seeing
The ECM monitors the pressure in the urea tank and system; it looks for pressures typically between 5-15 psi. If it exceeds that, it triggers this code.
What a healthy reading looks like
Urea system pressure should be between 5-15 psi during normal operation; a value over 15 psi can trigger this fault.
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 urea fluid level and quality; replace if contaminated or low.
- 2Inspect the pressure sensor harness for damage or corrosion; repair as needed.
- 3Use a scan tool to monitor urea pressure in real-time; confirm it exceeds 15 psi.
- 4Inspect urea lines for blockages; clear any obstructions if found.
- 5Test the pressure sensor; replace if it's faulty.
Common causes
- Faulty pressure sensor
- Blocked urea line
- Faulty pump affecting urea flow
- Contaminated urea causing pressure issues
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's not recommended to drive long distances with this code due to potential emissions issues.
Will this code come back after clearing it?
If the underlying issue isn't resolved, the code is likely to return.
Why does this code sometimes pair with P20C8?
P20C8 indicates a similar issue with urea system performance, often related to the same faults.
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