Code result
U05A3
Invalid Data Received From Reductant Quality Module
High severity
What it means
A receiving module detected implausible data from the reductant (DEF/AdBlue) quality sensor module. Concentration values fail plausibility checks and are rejected.
Is it safe to drive?
No — stop driving
This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly.
Most likely causes
Module internal fault or sensor input drift
highOne of the most commonly reported causes for this code — check this first.
Software version mismatch after replacement
mediumA plausible cause — test and verify before replacing parts.
Gateway module routing CAN messages incorrectly
lowLess common, but worth ruling out after the more likely causes.
Related help
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