Reductant Pressure Too High
Indicates that the pressure of the diesel exhaust fluid (DEF) is too high.
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 system that injects diesel exhaust fluid into the exhaust is sensing that the fluid pressure is above the normal range, which can affect how well the emissions are controlled.
What the computer is actually seeing
The vehicle's control unit is monitoring the pressure sensor in the DEF system. It expects the pressure to be between 1.5 to 4.5 bar (22 to 65 psi). If the pressure exceeds 4.5 bar, the code is triggered.
What a healthy reading looks like
Normal DEF pressure is between 1.5 to 4.5 bar (22 to 65 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.
- 11. Inspect the DEF reservoir for leaks or cracks. If found, repair or replace the reservoir. Decision: If reservoir is good, continue.
- 22. Check the connections to the DEF pressure sensor for corrosion or damage. Repair as necessary. Decision: If connections are good, continue.
- 33. Measure DEF pressure using a scan tool or gauge while running the engine. If pressure exceeds 4.5 bar, go to step 4. Decision: If pressure is normal, further diagnose the sensor.
- 44. Inspect the DEF lines for blockages or damage. Clear any blockages or replace damaged sections. Decision: If lines are clear, replace the DEF pressure sensor.
Common causes
- Faulty DEF pressure sensor
- Blocked DEF line
- Faulty DEF pump
- Kinked or damaged DEF line
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's generally safe to drive, but emissions may be impacted; fix soon.
Will this code come back if I clear it?
Yes, if the underlying issue isn't resolved, the code will likely return.
Why does this code pair with others?
Multiple codes can indicate issues with the DEF system that affect emissions.
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