Faulty Hybrid/EV Battery Pack Cooling Fan
Hybrid/EV Battery Pack Cooling Fan harness is open or shorted
Hybrid/EV Battery Pack Cooling Fan circuit poor electrical connection
Faulty Starter/Generator Control Module
Engine Light ON (or Service Engine Soon Warning Light)
The hybrid/EV battery pack cooling fan draws air through the hybrid/EV battery pack to control the temperature of the hybrid/EV battery pack. To operate, the cooling fan receives an enable signal from the starter/generator control module. The enable control is controlled by a discrete high side driver in the starter/generator control module. When the enable control circuit is high, the fan will be enabled. The fan speed is controlled by a fan control circuit from the starter/generator control module, by changing the duty cycle. The maximum fan speed is 3900 RPM. Hybrid/EV battery pack cooling fan enable circuit open and short to voltage diagnostics run continuously until hybrid/EV battery pack cooling fan is enabled to run while short to ground runs after it is enabled to run. These diagnostics detect and report a failure of the fan to enable circuits.