P21AF

Reductant Level Sensor C Circuit Low

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$33–89 (est.)

Symptoms

Check Engine light comes on
Increased emissions of harmful substances
Possible engine power limitation
Incorrect reductant level readings
Error message in the SCR system

Causes

Faulty reductant level sensor C
Open or short circuit in the sensor circuit
Poor connection or corrosion in connectors
Problems with the engine control unit (ECU)
Low level of reductant in the tank

How to Fix

Check the reductant level in the tank
Inspect the sensor wiring and connectors for damage
Check sensor resistance and voltage to specifications
Replace the faulty reductant level sensor if necessary
Reset the error code and check if it returns

Related codes

P21A0 P21A1 P21AE