Starter/Generator Control Module

The K59 Starter/Generator Control Module is a multifunction module that is involved in many eAssist system operations. Mounted in the engine compartment, the K59 Starter/Generator Control Module contains the K114A hybrid/EV powertrain control module 1, K107A drive motor 1 control module and the K1 14V Power Module.

The K114A hybrid/EV powertrain control module 1 is responsible for the following:

• Communicating with the K114B hybrid/EV powertrain control module 2 to determine the status of the high voltage battery
• Controlling the Starter/Generator cooling systems
• Host controller for DTC information for the K107A drive motor 1 control module and the K1 14V power module
• Supplying 12V to the vehicle

The K107A drive motor 1 control module is responsible for the following:

• Controlling the power inverter module, which converts high voltage direct current (DC) electrical energy to 3-phase alternating current (AC) electrical energy
• Monitoring the A15 starter/generator

The K1 14V power module converts high voltage (86V) direct current (DC) to low voltage (12V) DC for accessory electrical operation and to charge the 12V battery.

High Voltage Battery and Starter/Generator Cooling 

The K114B Hybrid/EV Powertrain Control Module 2 uses temperature information from the K112A/K112B hybrid battery interface control modules to control the high voltage battery cooling fan.

The K114A Hybrid/EV Powertrain Control Module 1 monitors the B235 Starter/Generator coolant temperature sensor and will control the KR133 Starter/Generator coolant pump relay, which in-turn controls the G43 Starter/Generator coolant pump.

High Voltage Isolation 

The K59 Starter/Generator Control Module and the K114B Hybrid/EV Powertrain Control Module 2 each monitor the electrical potential between high voltage and the vehicle chassis. High voltage should always be isolated from the vehicle chassis by a certain amount of resistance. In the event that a high voltage leak path is detected to the vehicle chassis, the applicable control module will set a DTC and open the high voltage contactors.

Testing for loss of isolation requires special tools and procedures. Because of the high voltages present in the hybrid system, a loss of isolation may occur due to insulation breakdown. Insulation breakdown typically occurs only when high voltage is present. Conditions such as insulation breakdown cannot be diagnosed with a typical DMM because high voltage is not used by the DMM when measuring resistance. Refer to Hybrid/EV System High Voltage Isolation Description .

12V Output 

The K1 14V Power Module within the K59 Starter/Generator Control Module essentially takes the place of the generator on a traditional vehicle. The K1 14V Power Module converts high voltage DC to 12-16V DC for accessory electrical operation and to charge the 12V battery.