Code result
P20AC
Reductant Metering Unit Temperature Sensor Circuit
Moderate severity
What it means
A general electrical fault is reported on the temperature sensor inside the DEF metering unit — used to protect the unit from over-temperature and to compensate for fluid viscosity.
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
Get the full diagnosis
Add your vehicle and see step-by-step repair help, recalls, and TSBs in Wrenchify.
Diagnose P20AC freeNo credit card required