Liebherr Fault Code
Free · no signupP1198
AdBlue Warning Light / Derate Active
System
Emissions / DEF
Symptom
AdBlue Warning Light / Derate Active
Diagnosis & fix steps
LOGIC: DEF Quality / Concentration Below Acceptable Minimum Limit.
ACTION: Test DEF concentration using a refractometer (spec: 32.5%). Drain contaminated DEF tank, flush with distilled water, and refill with fresh ISO 22241 DEF.
Red Seal field insights
Fluid Quality: Poor quality DEF prevents effective NOx conversion inside the SCR catalyst, initiating a timed inducement derate countdown.
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