P21DD

Reductant Heater A Current Too Low

Severity

🔴 High

Can you drive?

Limited driving only, diagnose soon

Approx. repair cost

$56–167 (est.)

Symptoms

Check engine light is on
Reduced engine power
SCR system malfunction message appears
Increased fuel consumption
Increased NOx emissions

Causes

Reagent heating element malfunction
Open or short circuit in the heater circuit
Problems with the heater circuit relay or fuse
Heater control module malfunction
Poor contact in heater circuit connectors

How to Fix

Check heater circuit fuse and relay
Check the integrity of wiring and connectors
Measure the resistance of the heating element
Check the operation of the heater control module
If necessary, replace the heating element or control module

Related codes

P20EE P21DA P21DE