P21A8
Reductant Level Sensor B Circuit
P21A8 is an OBD-II diagnostic trouble code meaning: Reductant Level Sensor B Circuit. Common causes: reductant level sensor fault b, open or short circuit in the sensor circuit. Estimated repair cost: $56–167.
Symptoms
- Check Engine light comes on
- Reduced engine power
- Increased fuel consumption
- SCR system error message on dashboard
- The engine may go into emergency mode
Causes
- Reductant level sensor fault B
- Open or short circuit in the sensor circuit
- Poor contact in the sensor connector
- Problems with the engine control unit (ECU)
- Sensor is dirty or damaged
How to Fix
- Check the integrity of the sensor circuit
- Inspect the connectors and contacts of the sensor
- Check the functionality of the reductant level sensor B
- Replace sensor if necessary
- Reset the error code and check the system
Related codes
Error P21A8 by Vehicle Brand
FAQ
What does the P21A8 code mean?
P21A8 is an OBD-II diagnostic trouble code that indicates: Reductant Level Sensor B Circuit
What causes a P21A8 error code?
The most common causes of P21A8 include: Reductant level sensor fault B; Open or short circuit in the sensor circuit; Poor contact in the sensor connector; Problems with the engine control unit (ECU).
How do I fix a P21A8 diagnostic trouble code?
To fix P21A8: Check the integrity of the sensor circuit. Inspect the connectors and contacts of the sensor. Check the functionality of the reductant level sensor B. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with P21A8?
Yes, but get it checked soon
How much does it cost to fix P21A8?
The estimated repair cost for P21A8 is $56–167. Actual cost depends on your vehicle, location, and labor rates.
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