Reductant Quality Sensor Range/Performance Problem
The reduction fluid quality sensor is detecting an issue with the quality of the diesel exhaust fluid (DEF).
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What it means (plain English)
The sensor that checks if the exhaust fluid is good or bad isn't reading right, which can happen if the fluid is contaminated or low.
What the computer is actually seeing
The powertrain control module (PCM) sees an abnormal signal coming from the reductant quality sensor, indicating that the fluid quality is below threshold levels, which is usually around 8 to 13 microsiemens/cm for DEF.
What a healthy reading looks like
A properly functioning reductant quality sensor should output a signal voltage that corresponds to valid fluid quality, typically between 0.5 to 4.5 volts under normal conditions.
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 condition and level of the diesel exhaust fluid; replace if contaminated or low.
- 2Inspect wiring and connectors at the reductant quality sensor for damage or corrosion; repair as necessary.
- 3Test the output voltage of the reductant quality sensor; should be between 0.5 to 4.5 volts. If not, consider replacing the sensor.
- 4Clear the code and perform a short test drive; see if the code returns.
Common causes
- Contaminated diesel exhaust fluid (DEF)
- Defective reductant quality sensor
- Corroded or damaged wiring/connectors in the sensor circuit
- Incorrect fluid type used (e.g., non-urea based fluid)
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It may still be driveable, but it can affect emissions and lead to reduced vehicle performance.
Will this code come back if I reset it?
If the underlying issue isn't resolved, the code will likely return after driving a certain distance.
Why does this code pair with other codes?
This often indicates multiple issues related to the DEF system, such as sensor failures or fluid quality problems.
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