Faulty Starter/Generator Coolant Pump Relay
Faulty Starter/Generator Coolant Pump
Starter/Generator Coolant Pump harness is open or shorted
Starter/Generator Coolant Pump circuit poor electrical connection
Faulty Starter/Generator Control Module
Engine Light ON (or Service Engine Soon Warning Light)
The Hybrid/EV Electronics Coolant Pump is a single-speed ON/OFF pump that circulates coolant through the auxiliary coolant radiator, starter/generator control module, and the starter/generator to control the temperature of these components.
The Enable and Feedback circuits allow the drive motor control module to control and monitor the Hybrid/EV Electronics Coolant Pump.
The Enable circuit controls the starter/generator coolant pump relay by applying ground to the relay coil control circuit. With the coil grounded, the relay switch is closed, and voltage is sent to the coolant pump, which begins circulating coolant.
The Hybrid/EV Electronics Coolant Pump utilizes a pulse-width modulated signal on the Feedback circuit to the drive motor control module. During normal operation, the feedback circuit provides pump speed information to the control module. If the Hybrid/EV Electronics Coolant Pump determines there is an internal fault it provides this information on the same feedback circuit instead of pump speed information. The starter/generator control module contains the Hybrid/EV Powertrain Control Module 1, drive motor control module, and the 14 V power module.
The Hybrid/EV Powertrain Control Module 1 will determine when a fault condition is present. Diagnostics and system status are communicated from the drive motor control module to the Hybrid/EV Powertrain Control Module 1 through internal serial data. The Hybrid/EV Powertrain Control Module 1 is the host controller for diagnostic trouble code information.
The Diagnostic Trouble Code (DTC) will be set if the Hybrid/EV Powertrain Control Module 1 detects the Coolant Pump Feedback circuit indicated pump speed is greater than 225 RPM when the pump is not enabled.