P21A8

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

1. Check the integrity of the sensor circuit
2. Inspect the connectors and contacts of the sensor
3. Check the functionality of the reductant level sensor B
4. Replace sensor if necessary
5. Reset the error code and check the system

Related codes

Error P21A8 by Vehicle Brand