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

12 V Output 

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