- Vehicle Management System (VMS)
- Fuse box
- Auxiliary Power Supply (APS) battery posts
- Power Electronics Module (PEM)
- Battery
- Service disconnect plug
- Inertia switch
- Switchpack
Electrical System
The vehicle's electrical system comprises of a number of electrical components that communicate with each other either via the hard wired electrical connections or using the Controller Area Network (CAN) bus/Local Interconnect Network (LIN) bus connections.
The vehicle wiring harness is constructed from copper cored wires split into a number of sections:
Each harness terminates with connectors that correspond with the connected components or harnesses.
NOTE: Use an aerosol based dielectric grease on the electrical connectors.
The front harness has five ground points on the body under the hood area on the RH side. The rear harness has two ground points on the body inboard of the RH rear wheel.
NOTE Use a proprietary brand of water resistant silicone based grease on electrical posts and ground points.
The inertia switch is located behind the LH rear wheel arch liner with a single electrical connector to the rear harness.
The fuse box is located behind the access panel on the RH side of the dash and contains the following fuses:
| Fuse | Rating (A) | Circuit Protected |
| 1 | 10 | Anti-lock Braking System (ABS) |
| 2 | 15 | Auxiliary power socket |
| 3 | 20 | Heating, Ventilation, Air Conditioning (HVAC) blower |
| 4 | 15 | Windshield wiper motor and washer |
| 5 | 7.5 | Electrical accessories, audio and navigation systems |
| 6 | 10 | Turn signals and side lights |
| 7 | 10 | Ignition services |
| 8 | 5 | Instrument pack and diagnostic socket |
| 9 | 10 | Horn |
| 10 | 7.5 | Interior light/trunk light |
| 11 | 20 | Interior lighting and seat heaters |
| 12 | 20 | Condenser cooling fan 1 |
| 13 | 20 | Condenser cooling fan 2 |
| 14 | 7.5 | Key in ACC position |
| 15 | 15 | LH headlight - low beam |
| 16 | 15 | RH headlight - low beam |
| 17 | 15 | LH headlight - high beam |
| 18 | 15 | RH headlight - high beam |
| 19 | 20 | Passenger’s window |
| 20 | 20 | Driver’s window |
| 21 | 10 | Central door locking |
| 22 | 7.5 | Brake vacuum pump |
| 23 | 15 | HVAC |
| 24 | 15 | Audio system amplifier |
| 25 | 30 | Key in ON position |
| 26 | 5 | Brake lights |
| 27 | 7.5 | HVAC control and satellite radio |
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WARNING: Always fit replacement fuses of the same rating and type or fuses of matching specification. Incorrect fuse ratings may overload a system and cause a fire or malfunction. No attempt should be made to repair a fuse that has blown. |
Controller Area Network (CAN) bus
The VMS uses a CAN bus to connect powertrain and safety critical systems. The CAN bus is a digital communication network used to split into four separate buses.
The electrical systems connected by the CAN 1 bus (1 mb/sec) are:
The electrical systems connected by the CAN 2 bus (125 kb/sec) are:
The electrical systems connected by the CAN 3 bus (500 kb/sec) are:
The RKE systems and GPS are connected directly to the VMS.
The VMS communicates over the CAN 4 bus (1 mb/sec) to the diagnostic socket is connected. The SRS and ABS communicate via a K-line to the diagnostic socket.
Local Interconnect Network (LIN) bus
The LIN bus is a digital communication network used to connect HomeLink® module to the VMS.
The unique feature of the vehicle is the method of energy storage. The energy that is used to drive the wheels via the motor and transmission is stored in the battery.
The battery is located in the rear of the vehicle between the passenger compartment and the trunk. The outer body of the battery comprises of an enclosure and a front cover. This encases all of the electrical cells that make up a sheet. The battery is constructed from 11 identical sheets connected in series. Each sheet is comprised of 9 bricks electrically connected in series. A brick is a group of 69 cells electrically connected in parallel. A cell refers to a single lithium-ion cell, 18 mm in diameter and 65 mm long each rated at 2.2A/h. A battery contains 6831 individual cells.
The Battery Monitor Board (BMB) is integrated into each sheet of the battery comprising of a voltage and temperature monitoring Printed Circuit Board (PCB). The BMB is responsible for monitoring battery voltage and temperature using a single temperature sensor placed within each brick. The BSM is a single PCB in the battery containing small microprocessors that monitor and control battery behavior.
| Feature | Specification |
| Capacity | 151.8A/h at 86°F (30°C) 140A/h at 14°F (-10°C) |
| Energy storage | 56kWh |
| Maximum total current output (5 seconds, 100% charge) | 650A |
| Maximum peak output (5 seconds) | 210kW at 411V |
| Peak charge current continuous | 111A |
| Peak regenerative current (30 seconds) | 238A |
A service disconnect receptacle is located on the RH side of the battery into which the service disconnect plug is fitted; this is used to isolate the electrical system during service procedures. To isolate the vehicle, lift the latch on the service plug then pull from the receptacle.
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CAUTION: To prevent damage to the Auxiliary Power Supply (APS) fuse located within the battery, the service plug should be removed and installed in one smooth operation. |
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CAUTION: To prevent damage to the APS fuse located within the battery, wait at least 120 seconds before reinstalling the service plug. |
The installation procedure is the reverse of removal. Refer to FRT 16010002 in the Service Manual for procedure details.
Power Electronics Module (PEM)
The PEM is a sister module to the battery that houses the Direct Current/Alternating Current (DC/AC) inverter for the motor, the AC/DC rectifier for charging, and the control circuits for drive and charging. It is connected to the front harness using three connectors. For further information, refer to this information. .
Vehicle Management System (VMS)
The VMS is located on the underside of the dash on the passenger side. It is connected to the front harness using three connectors. The VMS monitors, controls and coordinates various systems in the vehicle including the PEM, battery and HVAC system.
The switchpack is located under the upper dash trim and is connected to the front harness using five connectors.
The APS is a DC/DC switch mode power supply located within the battery which converts vehicle battery voltage (nominally 360V) to two separate outputs:
The purpose of the wiring harness is to distribute electrical power and signals to the electrical components within the vehicle to operate the various electrical systems. Fuses are fitted within various electrical circuits to protect the wiring harness from damage in the event of component failure or short circuits. In the event of a collision, the inertia switch will trip and inhibit the operation of the vehicle electrical systems.
The use of digital communication, or multiplexing, between ECUs allows a reduction in size and complexity of vehicle wiring harnesses. The advantage of multiplexing is that information that is available from one sensor can be shared between many ECUs. For instance, the vehicle speed signal produced by the Anti-lock Braking System (ABS) ECU is shared between the ABS and the traction control system.
Controller Area Network (CAN) bus
The CAN bus is a high speed, digital broadcast network comprising two wires, identified as CAN Low (L) and CAN High (H), twisted together to minimise the electromagnetic interference (noise) produced by the CAN signals. Signals consist of a voltage which is simultaneously transmitted, in opposite phase, on both wires. CAN L switches between 2.5V and 1.5V while CAN H switches between 2.5V and 3.5V, which causes the potential difference between the two lines to switch between 0V (logic 1) and 2V (logic 0) to produce the digital signal message. The CAN bus links together the ECUs and components in the network. Each component in the network decodes the signals on the CAN bus into the information it needs to perform its task, a process known as multiplexing. The CAN bus is capable of managing real time information required by the powertrain control systems.
Local Interconnect Network (LIN) bus
The LIN bus is a short distance low speed network, the 'bus' is a single line harness. The LIN bus switches between 12V (logic 1) and 0V (logic 0). The LIN bus connects all of the ECUs on the network. The Vehicle Management System (VMS) decodes the signals on the LIN bus and uses the CAN bus to perform the tasks. The advantage of the LIN bus is its simple construction which can carry one way or two way communication via a single chip.
The ignition switch has 4 positions, each allowing different vehicle functionality. These are:
NOTE: If the vehicle does not successfully enter Drive due to driver error (brake pedal not depressed, etc.), an appropriate message will be shown on the touch screen, an audible alert will sound and the Park indicator 'P' will flash green until the user retries the start sequence.
NOTE: When the is in the OFF position it will retain it's previous state, i.e. If the key was in the ACC position, ACC remains active. This means the key states remain active until the key is removed. But when re-inserting the key, the key must be turned to ACC or START to activate them.
If the charge port door is opened when the key is in ACC, ON or START, the vehicle will illuminate a warning indicator until it is shut. The vehicle will never enter the Charge state when the key is in any of these positions. If the vehicle is already in the Charge state when the key is turned to START, the vehicle will be prohibited from starting; if the contactors are open, pre-charge will not occur, the transmission parking pawl will remain engaged, a warning indicator will illuminate and a message will appear on the touch screen until the charge port door is shut.
The following table is a list of key behaviors and corresponding test procedures with the key in various positions:
| Description | Procedure |
| An audible warning to the driver is activated whenever the key has been left in the ignition switch and the driver's door is opened. The warning does not operate after the key has been removed. | Open door with key in ignition switch, turn key to off and partially remove key. |
| An audible warning to the driver is activated whenever the key has been left in the ignition switch and the driver's door is opened. The warning does not operate when the key is in the ON or START positions. | Open door when key is in both ON and START positions. |
| An audible warning to the driver is activated whenever the key has been left in the ignition switch and the driver's door is opened. The warning does not operate after the key has been inserted in the ignition switch and before it has been turned. | Insert key into ignition switch, do not turn, open door. |
| While the key is in the ACC or ON position, the APS will remain on unless it is necessary to turn off to protect the battery from over-discharge. | Turn key to ACC, leave car for over 5 minutes, check that APS does not time out. The interior light should operate if APS active. |
| While the key is in the ACC or ON position, power will be supplied to the brake lights, radio, windshield wiper, window motors, seat heaters, cabin fan, HVAC control panel, SRS, brake vacuum booster, and TPMS. | Turn key to ACC, leave car for over 5 minutes, check that all listed controls are still operational. |
| While the key is in the ON position and the contactors are closed, cabin heating and cooling will be operational. | Check that cabin heating and cooling are not operational when contactors are open, try with key OFF and in ACC position. Turn key to ON, check that both are now operational. |
| When moving the key from ACC to ON, the contactors will be commanded to close. | Turn key from ACC to ON, check that contactors close. |
| When moving the key from ON to ACC, the contactors will be commanded open. | Turn key from ON to ACC, check that contactors open. |
| When key is turned from ON to ACC, the parking pawl will be commanded to engage once wheel speed is less than 1.4 mph. | Drive vehicle and turn key to ACC. Check transmission lock engagement speed in both forward and reverse drive. |
| If the key is moved from ACC to ON while the parking pawl is retracted, the vehicle will enter Neutral. | - |
| The vehicle will not close contactors when the key is turned from ACC to ON if the charge port door is open or a pilot signal is detected. | Turn off APS, turn on interior light, turn on APS. The interior light should only operate if APS already on. |
| When the contactors close, an audible notification is activated. | Turned key to ON. Check that the transmission lock is still engaged. |
| With the key is in the OFF position, the APS will shut down. | Turned key to ON. Leave vehicle for longer than 15 minutes and check that the APS does not time out. The interior light should operate if APS active. |
The battery stores electrical energy which is converted into kinetic energy by the motor. This energy is used to drive the vehicle.
Under normal conditions, the Battery Safety Monitor (BSM) operates the main battery contactor in response to commands received from the Vehicle Management System (VMS). The VMS will instruct the BSM to energize the contactor in anticipation of driving or charging. Typically this would be when the key is in ON position, or when the charge cable is connected in anticipation of charging the battery. The VMS will command the BSM to open the contactor when the key is moved to the ACC position.
The BSM performs the following functions:
The following are inputs to the BSM:
The following are outputs from the BSM:
High Voltage Interlock Loop (HVIL)
The HVIL is a monitoring system embedded in the BSM used to monitor the battery high voltage circuit. The system is designed to shut down the high voltage electrical systems if the HVIL is broken in the event of a collision or not allow the high voltage battery contactors to close if the loop is opened. If the HVIL is broken, high voltage is immediately removed from the high voltage components and the system is discharged.
The HVIL can be also be broken if the following conditions occur:
NOTE: It may not always be obvious when the HVIL is broken. A blown fuse in the battery to 400V controller will not be detected by the VMS or any other module.
Battery Ground Fault Detection
Low impedance between the battery and the conductive parts of the vehicle structure may occur at:
The battery has a high valued resistive center tap to the vehicle chassis. All devices connected to the battery bus are designed to have reinforced grade insulation between the battery bus connected circuits and the remaining parts of the device. If the current flowing through the resistive center tap to chassis exceeds a specified threshold, an unacceptably low resistance exists from one of the battery bus cables to chassis. Measuring the current to ground from the taps alternately (with filtering to eliminate false triggering due to noise) reveals the presence of unacceptably low impedance to chassis. The fault condition is used to take some corrective action, such as preventing charging or drive
Battery overvoltage protection means the vehicle will protect itself from an over voltage condition. If these overvoltage occurs, the BSM will open the main contactor. The BSM will not close the contactor until it receives a specific command from the VMS or the diagnostic tool. This is to prevent a cycle of overvolt trip – contactor release – voltage OK – contractor closes – charging commences – overvolt trip.
The thresholds set in the BSM for taking these actions are above the normal operating limits of VMS controlled charging. A normally functioning PEM will also detect VMS failure and terminate charging well before the limits set in the BSM are exceeded. Opening the contactor will cause the voltage at the charger output to rise, possibly high enough to damage it and other devices connected to the external 400V bus.
The VMS, monitors battery operating conditions and takes action before the battery is completely discharged. The BSM provides a simple back-up mechanism should the VMS fail. Battery voltage depends on load current as well as state of charge. The undervolt threshold is set to ensure that the state of charge never goes below the danger point. If the battery output current is not zero, the undervolt condition will occur while the state of charge is still acceptable. If the battery voltage is below the undervolt threshold for more than one minute, the state of charge is dangerously low.
Once the low state-of-charge condition occurs, the BSM will attempt to shed load to prevent the battery discharging further. Load shedding can occur through the following mechanisms:
If the battery monitor and BSM power consumption is low, compared to the battery’s self-discharge rate it may be permissible to leave them energized permanently. The undervolt condition must be recognized by the PEM and/or VMS so charging current can be reduced until the battery state of charge is high enough to accept full charging current.
The BSM will report environmental conditions within the battery to the VMS. With the exception of some emergency conditions, all heating and cooling operations are controlled by devices external to the battery box. The following emergency conditions will cause the battery contractors to be opened:
The BSM latches into the overvolt trip condition. The BSM must have the overvolt state reset after the cause of the overvolt condition has been rectified. This can be achieved by cycling the ignition.
If the BSM shuts down completely due to battery undervolt, the state of charge is too low to supply any power and a recovery charge will need to be performed.
If the battery voltage is less than 250V and any individual sheet voltage is below approximately 20V, then the low voltage alert for that sheet must be disabled using the diagnostic tool and a recovery charge must be performed. At this low voltage, the onboard vehicle charge system is inoperable. The recovery charge is performed by charging through the high voltage PEM to battery connector HVC3 on the RH side of the PEM. If brick voltage is below 3V, recovery charging should be conducted at less than 15A (DC) and for no more than 90 minutes (assuming 15A). During this time, a technician must be present to monitor the charge and ensure it completes successfully and to avoid charging cells/bricks that have failed. If after 90 minutes, brick is not above 3V, there may be a problem with a cell/brick.
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WARNING: Battery sheet modules containing Lithium-ion cells that have currently or previously fallen below 2.0V open circuit are not validated for recharging or re-use and should be replaced. Recharging Lithium-ion cells below this threshold can cause immediate or latent damage, creating a hazardous condition from the dissolved copper or other degradation mechanisms which can lead to fire, property damage, electrical shock, serious injury and/or death. Only perform recharging procedures specified in the service manual and follow all applicable instructions. |
Once the battery voltage has been increased to 360V, the vehicle can be charged as normal using the charge port.
The CSB is a processor integrated into the BSM. It performs the following functions:
Vehicle Management System (VMS)
The VMS is made up from a number of processors:
Serial interface circuits in the various ECUs transmit and receive commands on the buses as digital messages. ECUs connected to the same bus use a common protocol (format) and baud rate (transmission period) for the messages they transmit. To enable messages to be exchanged between ECUs on the CAN and LIN buses, the VMS provides a communication gateway converting and re-transmitting messages on the relevant buses.
The switchpack module acts as a buffer between low current control devices and high-current loads. For example, it turns on the headlights when it receives a logic signal from a switch, removing the need for the switch to have to carry the headlight load, and also allowing the addition of inrush current limiting. Inrush current is the maximum, instantaneous input current drawn by an electrical component when it is first switched on. The module receives input directly from switches, and also via the CAN bus from the VMS. The module reports status back to the VMS via the CAN bus.
The switchpack has the following inputs:
The switchpack has the following outputs:
The switchpack has the following in/out power signals:
The switchpack also monitors:
The vehicle's lighting system operates using the 12V supply from the APS.
The headlight switch has three positions, 'OFF', 'Side and License Plate Lights' and 'ON'.
If the headlight light switch is ON and the key is removed from the vehicle, the headlights will extinguish. The headlights can be switched back on by cycling the headlight switch and the lights will remain on until the headlight switch is turned OFF. If the switch is left in the ON position, headlights will not automatically turn back on when the vehicle sees the key again in ACC. An audible alert will sound any time the key is OFF, the headlights are on and a door is opened. When the switch is moved from OFF to the second position, the front and side, license plate and tail lights will be illuminated. Interior backlighting will only be illuminated if the key is not in the OFF position.
NOTE: If low beams are turned on by the user and both are not functioning, the high beams will turn on in less than 1 second.
While the key is in the ON position, if the LH steering column stalk is pulled toward the driver, high beam headlights will be activated until the stalk is released, regardless of headlight switch position. The blue high beam indicator on the instrument pack will illuminate while the headlights are in high beam.
The hazard lights will illuminate and flash, regardless of whether or not the key is in the ACC or ON positions, whenever the hazard light switch is depressed. An audible indicator will sound and both turn signal indicators on the instrument pack and the hazard switch light will illuminate and flash any time the switch is engaged. The lights will extinguish once the switch is pressed again. The switch shall be dimly backlit whenever the master lighting switch is in any position other than OFF and the hazard function is not active.
Selection and validation of reverse gear causes a driver on the Digital Motor Controller (DMC), the control module for the drive and charging systems, to apply 12V to the white LED reverse lights. The driver limits current to less than 5 amps.
The brake pedal operates the brake light switch which is also connected to the PEM. This connection provides brake inputs and also brake light outputs during regenerative braking (regen). The DMC triggers the brake lights when it detects a set amount of negative torque during regen.
The interior light, located between the tops of passenger seats, is its own switch. It has three positions:
When the throttle pedal is release and regenerative braking (regen) occurs, the motor, wheels are braking system experience the following torques:
| Description | Reverse | Forward |
| Peak regen torque at motor | 50 Nm | 55 Nm |
| Peak regen torque at wheels | 675 Nm | 410 Nm |
| Brake light threshold at motor | 17.4 Nm | 30 Nm |