Code result
P203A
Reductant Level Sensor A Circuit
Moderate severity
What it means
A general electrical fault is reported on DEF level sensor A — open, shorted, or out of plausibility. Some tanks use multiple level senders to cover irregular tank shapes; this is the primary one.
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
Sender failed — float, swing arm, or rheostat
highOne of the most commonly reported causes for this code — check this first.
Harness or connector fault
mediumA plausible cause — test and verify before replacing parts.
Related help
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