Plug-In Hybrid Electric Vehicle Battery Temperature Control System

WARNING: This page is about a different variant/trim than selected.

WARNING: Do not do any work on the HV system until the HV system on the vehicle is powered down.

The BECM monitors the internal temperature of the PHEV battery when the vehicle is driven or the PHEV battery is charging.

The BECM uses temperature data from sensors positioned inside the PHEV battery. The BECM is part of the PHEV battery.

The temperature sensors used to monitor the internal temperature of the PHEV battery are of the Negative Temperature Coefficient (NTC) resistors type. The data from the temperature sensors is used by the BECM to regulate the internal temperature of the PHEV battery. If the PHEV battery internal temperature exceeds specified limits the BECM will decrease the power available from the PHEV battery.

The PHEV battery coolant heater is only used when the vehicle is connected to an external charging point.

If the internal temperature of the PHEV battery is less than a specified temperature the BECM will activate:

The PHEV battery coolant pump
The PHEV battery coolant heater.

This will heat the PHEV battery coolant and circulate it through the PHEV battery to increase the internal temperature of the PHEV battery.

If the internal temperature of the PHEV battery is more than a specified temperature the BECM will activate the PHEV battery coolant pump.

The coolant will either:

Flow through the PHEV battery coolant cooler. The BECM will send a message to the HVAC control module to activate the PHEV battery coolant cooler connected to the A/C system. The HVAC control module will then activate the following:
- The electric A/C compressor.
- The PHEV battery coolant cooler.
Flow through the PHEV battery coolant low temperature radiator.

The flow is controlled by the coolant diverter valve.