Reductant Quality Module

WARNING: This page is about a different car, the 2021 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.

The reductant quality module provides the reductant tank level and reductant concentration to the PCM. The reductant quality module incorporates an ultrasonic transducer and sensor assembly, located at the bottom of the reductant tank. The transducer produces timed ultrasonic sound waves through the DEF (diesel exhaust fluid) and the sensor measures the return rate of the sound waves. As the DEF is consumed, the liquid level lowers and the return speed increases. Additionally, the sensor monitors reductant concentration percentage by calculating the speed of sound travel through the DEF and comparing it to an expected value. If this value is not met, the reductant is diluted or contaminated. The reductant quality module is integral to the reductant tank assembly.