Reductant Pressure Too Low
The system has detected low pressure in the reductant (urea) system.
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 is seeing that the pressure of the fluid used in the system to reduce emissions isn’t high enough, which could cause the emissions system to not work properly.
What the computer is actually seeing
The reductant pressure sensor is reading below the minimum threshold, typically below 2.5 PSI, which indicates insufficient pressure in the DEF system.
What a healthy reading looks like
Reductant pressure should be between 5 and 13 PSI during operation.
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 fluid level—ensure it is above the minimum mark.
- 22. Inspect all hoses and connections in the DEF system for leaks or damage.
- 33. Test the reductant pressure sensor—using a multimeter, check for proper voltage output, which should be around 0.5 to 4.5 volts.
- 44. If the sensor is faulty, replace it and clear the code; retest.
- 55. If the pressure is still low, test the supply pump for proper operation and pressure output.
Common causes
- Faulty reductant pressure sensor
- Leaking hoses or connections
- Low DEF (Diesel Exhaust Fluid) level
- Faulty pump or injector
- Blocked DEF lines
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's drivable but emissions may be higher; fix soon to avoid larger problems.
Will this code come back after repair?
If repairs are well done and issues are fully resolved, it should not reappear.
Why does it pair with P20C7?
P20C7 is related to the same system; if the sensor fails, it can trigger multiple codes.
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