Update Your Ford Workshop Library 2006 Ford Escape Hybrid Courtesy Ford Motor Company High-Voltage Traction Battery (HVTB) The high voltage system has a float- ing ground. When the engine is operat- ing or the vehicle is moving, the high voltage generator begins to generate high voltage alternating current (AC) electricity. High voltage AC electricity can be consumed or generated by the motor generator, the traction motor, or a combination of both motors. Excess high voltage current is converted from high voltage AC to high voltage direct current (DC) electrical power inside the motor generator unit and transmitted through the high voltage cables. The high voltage DC electrical power is con- verted to low voltage DC electrical power through the DC/DC converter. This low voltage DC electrical power is then supplied to the 12 volt battery through the low voltage battery cables. The 12 volt battery is a standard auto- motive battery. It is a DC source connect- ed in a negative ground system. The bat- tery case is sealed, with two vent holes to release gases. The battery has three major functions: storage of electricity for later use, voltage stabilizer for the electrical system, and temporary power source when electrical loads exceed the DC/DC converter output current. CAUTION: Before placing the vehicle in a paint booth, the HVTB must be removed to avoid heat damage. The HVTB is a 216-397 volts DC source connected in a floating ground system. The battery receives, stores, and delivers high voltage electrical power when required. It contains the traction battery control module (TBCM), which controls the higher functions of the battery. The TBCM also estimates the state of charge, estimates the power available, and controls the battery temperature. The TBCM controls the battery temperature by activating or deactivating the fans contained within the HVTB, and by activating or deacti- vating the air conditioning system for the HVTB. Also contained within the HVTB is a low voltage charger that is used during the jump start procedure. For information about the jump start procedure, refer to the Owner Literature. Motor Generator The motor generator is contained in the electronically controlled continuous- ly variable transmission (eCVT). It functions to generate high voltage elec- tricity and as the starter motor. The motor generator is connected to the HVTB with the high voltage cables. The motor generator is an internal part of the eCVT and it cannot be repaired, only replaced as a new assembly. DC/DC Converter The DC/DC converter is a liquid- cooled component that converts high voltage (216-397 volts) DC power to low voltage (12 volts) DC power while maintaining electrical isolation between the two DC power systems. The con- verter steps down the high voltage to 12 volts, providing power to the vehicle low voltage battery systems. The pow- ertrain control module (PCM) controls the operation of the DC/DC converter through an enable input from the PCM to the DC/DC converter. Regenerative Brakes The regenerative braking system is designed to recapture some of the energy from braking. It accomplishes this through the use of the traction motor and motor generator, which recapture energy during braking. This recaptured energy is used to charge the HVTB. The regenerative brake system is a series system. A series system is one in which powertrain braking is used first, up to the limits of the powertrain torque capacity and battery capacity. After optimum regen- eration is used, the friction brakes are applied to supplement _ braking demands. The series regenerative brak- ing system also contains the anti-lock brake system (ABS) module within the same unit. High-Voltage Converter /Inverter DC/AC Inverter and AC Power Point The DC/AC inverter converts 12 volts DC to 110 volts AC to power a device that uses AC current with a rating of less than 150 watts. DC/DC Converter The DC/DC converter is a liquid- cooled component that converts high voltage (216-397 volts) DC power to low voltage (12 volts) DC power while maintaining electrical isolation between the two DC power systems. The convert- er steps down the high voltage to 12 volts, providing power to the vehicle low voltage battery systems. The PCM controls the operation of the DC/DC converter through an enable input from the PCM to the DC/DC converter. Communications Network-Hybrid Smart Junction Box (SJB) The SJB is connected to the medium speed controller area network (CAN) communications bus. If one of the bus wires becomes shorted to ground or voltage, communications can continue at a reduced level. Check circuits 1847 (WH/OG), and 1848 (PK/OG) between the SJB C2280a, the instrument cluster C220 and the data link connector (DLC) C251. Total resistance values must not be more than 5 ohms. If the resistance is more than 5 ohms, there is an open circuit in the medium speed CAN, dam- age to the DLC C251, or damage to the SJB C2280a. Since both the SJB and the instrument c