Code result
U05A4
Particulate Matter Sensor Received Invalid Data From ECM/PCM
Moderate severity
What it means
The particulate matter (PM) sensor (smart sensor with own ECU) received implausible data from the ECM/PCM. Engine load, exhaust temperature or DPF state data needed for compensation fails plausibility checks; PM readings are degraded.
Is it safe to drive?
Use caution
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
ECM/PCM 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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