Circuit/System Description

The reductant pump motor is controlled by the reductant control module. The engine control module (ECM) sends a command to the reductant control module via direct wire connection. This command is converted by the reductant control module into a desired pump speed The ECM checks the state of the wire to the reductant control module for circuit continuity. The signal sent by the ECM to the reductant control module is diagnosed for open circuit, short circuit to ground, and short circuit to voltage.