P21C6

Reductant Level Sensor B Stuck

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$39–133 (est.)

Symptoms

Check Engine Light
Low AdBlue message on the dashboard
Engine power limitation
Incorrect reagent level readings
Inability to refill the AdBlue system

Causes

Level sensor float jammed
Mechanical damage to the sensor
Sensor contamination with urea crystals
Open or short circuit in the sensor circuit
Level sensor module malfunction

How to Fix

Visual inspection of the level sensor for mechanical damage
Cleaning the sensor and tank from crystallized urea
Checking the sensor electrical circuit for opens and short circuits
Replacing the reagent level sensor
Resetting the error and testing the system

Related codes

P203F P204F P205F