P05F8

Symptoms

• AdBlue/SCR system fault warning
• Check Engine Light Is On
• AdBlue freezing in cold weather (insufficient heating)
• Ammonia smell (reagent overheating)
• Unstable operation of the SCR system at low temperatures

Causes

• Heater control module internal fault
• Faulty AdBlue reagent temperature sensor
• Heating element malfunction (burnout)
• AdBlue system is dirty or clogged
• AdBlue ECU malfunction

How to Fix

1. Read codes using a specialized scanner for the SCR/AdBlue system
2. Check AdBlue temperature sensor
3. Check the heating element of the tank for integrity (measure resistance)
4. Check the heating elements of the AdBlue lines
5. Check power supply and control signals of the heater module
6. Diagnose or replace AdBlue heater control module

Related codes

Error P05F8 by Vehicle Brand