Reductant Quality Sensor Range/Performance Problem
The reductant quality sensor is detecting an issue with the quality of the diesel exhaust fluid (DEF).
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 thinks the DEF being used isn't up to spec, which can be caused by using poor quality DEF or having contamination in the tank.
What the computer is actually seeing
The sensor measures the conductivity and temperature of the DEF. Normal conductivity should be within a specific range, typically 1,000-1,400 µS/cm at 20°C. If conductivity is too low or too high, it triggers this code.
What a healthy reading looks like
Conductivity: 1,000-1,400 µS/cm, Temperature: -11°C to 32°C (normal operating range).
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 quality: Make sure it's genuine, uncontaminated, and hasn't been sitting too long in extreme temperatures.
- 22. Inspect the wiring and connectors to the reductant quality sensor for signs of damage or corrosion. Repair or replace as necessary.
- 33. Measure the DEF temperature using a scan tool to ensure it’s within normal operating range.
- 44. Test the reductant quality sensor’s output with a multimeter, checking conductivity and other signals against expected values.
- 55. If all checks are within spec, consider replacing the reductant quality sensor.
Common causes
- Contaminated DEF (like water or fuel mixed in)
- Faulty reductant quality sensor
- Wiring or connector issues to the sensor
- Poor quality DEF
- DEF tank or lines damage
Typical repair cost
$$$
Related codes
Frequently asked questions
Can I still drive with this code?
Yes, but it's advisable to address it soon to avoid emissions issues and possible limp mode.
Will this code come back after I clear it?
If the underlying issue isn't fixed, the code is likely to return.
Why did this code appear with other DEF-related codes?
Multiple codes can indicate a broader problem with the DEF system, such as contamination or sensor failure.
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