Code result
P2042
Reductant Temperature Sensor A Circuit
Moderate severity
What it means
A general electrical fault is reported on reductant (DEF) temperature sensor A — used to compensate dosing for fluid viscosity and to enable tank heating in winter.
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
Sensor element failed
highOne of the most commonly reported causes for this code — check this first.
Harness fault
mediumA plausible cause — test and verify before replacing parts.
Related help
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