Reductant Level Sensor B Circuit Range/Performance

Where it lives

For P21A9, start at the sensor the description names.

Check these first

• A reductant level sensor B reading outside its range
• A failed sensing element inside sensor B
• Corrosion or water in the sensor B connector
• Urea crystallization on sensor B
• An incorrect sensor B for the vehicle

What to do next

1. Read the reductant level sensor B value on a scan tool
2. Compare the sensor B reading to the tank level
3. Inspect the sensor B connector for corrosion or water
4. Clean the sensor B of urea crystallization
5. Replace the reductant level sensor B if the reading stays skewed
6. Clear the code and retest

Look up another code