< Назад | Содержимое | Далее >

‌ELECTRICAL

Wiring Systems and Power Management - Description and Operation - Volt

DESCRIPTION AND OPERATION

ELECTRONIC PARK LOCK DESCRIPTION AND OPERATION

If the vehicle is equipped with automatic transmission and a floor mounted console gear shift, it has an electronic park lock system. The electronic park lock system purpose is to prevent the ignition from being switched to the Vehicle OFF position when the transmission is in any position other than PARK and the vehicle may still be moving. The electronic park lock system incorporates the park position switch that located in the A/T shift lock control switch. When the transmission shift selector is in PARK, the park position switch closes and the BCM allows the ignition to be turned Vehicle OFF.

If the vehicle is not in PARK, the ignition will return to ACC/ACCESSORY and display the message SHIFT TO PARK in the Driver Information Center. When the vehicle is shifted into PARK, the ignition system will switch to Vehicle OFF.

POWER MODE DESCRIPTION AND OPERATION

Fig. 1: Power Mode System Block Diagram Courtesy of GENERAL MOTORS COMPANY

Serial Data Power Mode Master

Power to many of this vehicles circuits is controlled by the module that is designated the power mode master. This vehicles power mode master is the body control module (BCM). The BCM has multiple B+ circuits that feed into it. Each of those circuits are partitioned within the controller to drive certain outputs of the vehicle's body functions. An open or short in any one of the B+ circuits may induce multiple codes/or a section of non- functionality within the BCM with the rest of the BCM functioning normally. In this case it is useful to refer to the power distribution schematics to determine if the non-functional partition of the controller shares a common B+ circuit. The power button switch is a low current push button switch with discrete power button switch signals to the power mode master for determination of the power mode that will be sent over the serial data circuits to the other modules that need this information. The power mode master will also activate relays and other direct outputs of the power mode master as needed. The power mode master determines which power mode (Vehicle Off, Vehicle On, Vehicle in Service Mode) is required, and reports this information to other modules via serial data. Modules which have switched voltage inputs may operate in a default mode if the power mode serial data message does not match what the individual module can see from its own connections.

The power mode master receives power button switch signals and transmitter in range signals to identify the operators desired power mode. The Power Mode Parameters table below illustrates the correct state of these input parameters (circuits) in correspondence to the power button switch position and the transmitter to vehicle range:

Power Mode Parameters

Relay Controlled Power Mode

The BCM uses the discrete power button switch inputs, transmitter in range status, current power mode state, and the brake pedal position state to distinguish the correct power mode (Vehicle Off, Vehicle On, and Vehicle in Service Mode). The BCM, after determining the desired power mode, will activate the appropriate relays for that power mode and send the power mode message out to other modules in a serial data message.

The retained accessory power relay remains on for a timed period after the power mode transitions to Vehicle Off. Refer to Retained Accessory Power Description and Operation for more information on the retained accessory power function.

Push Button Start

The vehicle has an electronic push button start switch. The power button switch is equipped with two LED's, one for backlighting and one for Vehicle On indication or Vehicle In Service Mode indication. The power button switch light flashes when the driver door is open and the vehicle is not on. The flashing light will eventually time out. The power button switch light is on steady when in Vehicle On or Vehicle In Service Mode. When the vehicle is turned off, the power button switch light will turn off.

Vehicle On

This position is for driving and starting. The Vehicle On mode will be used for service (including maintenance and lubrication) and diagnostics on the electronic propulsion system or the gas engine. With the vehicle off,

transmitter in the vehicle and the brake pedal applied, pressing the power button switch once will place the vehicle in Vehicle On mode. The instrument cluster displays an active fuel or battery gauge, along with an audio startup cue, when the vehicle is ready to be driven. This could take up to 15 s at extremely cold temperatures.

The gas engine will only start if needed. If the vehicle did not start, the instrument cluster will display a screen with inactive fuel and battery gauges. The electric propulsion system is active in this power mode. The gas engine will start if the hood is opened while in this power mode. The vehicle can be charged while in this power mode. If the vehicle is left in PARK while in Vehicle On mode and the transmitter is removed from the vehicle, the vehicle will automatically turn off after 1.5 hours. If the vehicle is left in PARK while in Vehicle On mode and the transmitter is in the vehicle, the vehicle will automatically turn OFF after 3 hours. The timer will stop when the vehicle is shifted out of PARK and the timer will reset after the vehicle is placed back in PARK while in Vehicle On mode.

Vehicle In Service Mode

NOTE: The vehicle will not charge if the charging cable is attached to the vehicle after being placed into the Vehicle In Service Mode. Attach the charging cable to the vehicle before entering the Vehicle In Service Mode to charge the vehicle.

This power mode is available for service and diagnostics, and to verify the proper operation of the MIL as may be required for emission inspection purposes. The Vehicle In Service Mode will be used for service and diagnostics for items not requiring the electronic propulsion to be active or the operation of the gas engine. With the vehicle off, and the brake pedal not applied, pressing and holding the power button switch for 5 s will place the vehicle in Vehicle In Service Mode for approximately 3 hours. After being in Vehicle In Service Mode for

1.5 hours, the vehicle will look to see if the transmitter in still present. If the transmitter is not present in the vehicle, it will power down instead of staying powered up for the full 3 hours. Pressing and holding the power button switch for at least 10 s will place the vehicle in Vehicle In Service Mode until the vehicle is manually turned OFF. The instruments and audio systems will operate as they do in Vehicle On mode, but the vehicle will not be able to be driven. The electric propulsion system is inactive in this power mode. The gas engine will not start if the hood is opened while in this power mode. The vehicle can only be charged in this power mode if the charging cable is attached before this power mode is enabled.

Vehicle Off

To turn the vehicle off, push the power button switch with the vehicle in P (Park). Retained Accessory Power (RAP) will remain active until the driver door is opened. Refer to Retained Accessory Power Description and Operation for more information on the retained accessory power function. When turning off the vehicle, if the vehicle is not in P (Park), the SHIFT TO PARK message is displayed in the Driver Information Center (DIC).

The electric propulsion system is inactive in this power mode. The gas engine will not start if the hood is opened in this power mode. The vehicle can be charged while in this power mode.

Battery Saver Mode (Transport Mode) (If Equipped)

The battery saver mode (transport mode) reduces the parasitic load of some modules during overseas shipment or during vehicle storage conditions. This improves the drain time on the battery (up to 70 days without the battery going dead). When the vehicle is in transport/storage, some features may have reduced functionality while in the battery saver mode (transport mode), such as disabling the Remote Function Actuator or content theft features.

The battery saver mode (transport mode) incorporates a latching relay that when enabled disconnects some modules from their ignition power or memory power sources. Battery saver mode (transport mode) is initiated by turning on the hazard flashers, applying the brake pedal, and then pushing the power button switch for greater than 15 s. The mode is disengaged by repeating the previous process causing the relay to latch in the

other direction. Once the vehicle is in Vehicle On mode and the hazard flashers are on, pushing the power button switch for greater than 15 s will latch the relay in the other direction. This feature can be used as many times as necessary if the vehicle is to be stored for an extended period of time.

BCM Awake/Sleep States

The BCM is able to control or perform all of the BCM functions in the awake state. The BCM enters the sleep state when active control or normal monitoring of system functions has stopped and a time limit has passed. The BCM must detect certain wake-up inputs before entering the awake state. The BCM monitors for these inputs during the sleep state.

The BCM will enter the awake state if any of the following wake-up inputs are detected: Activity on the serial data line (including wake-up circuits)

Detection of a battery reconnect Any door open signal

Headlamps ON Vehicle On

Vehicle In Service Mode Park lamps ON

Keyless entry or remote start message

The BCM will enter a sleep state when all of the following conditions exist: Vehicle Off, transmitter is out of range

No activity exists on the serial data line (including wake-up circuits) No outputs are commanded.

No delay timers are actively counting. No wake-up inputs are present.

If all these conditions are met, the BCM will enter a low power or sleep condition.

Serial Data Wake-Up

Control modules on the serial data wake-up circuit enable or disable communication based on the voltage level of this circuit.

RETAINED ACCESSORY POWER DESCRIPTION AND OPERATION

Fig. 2: 16 Volt Retained Accessory Power System Block Diagram Courtesy of GENERAL MOTORS COMPANY

Retained Accessory Power

The body control module (BCM) monitors the vehicle power modes, battery condition, and each door ajar/open switch status to determine whether the retained accessory power should be initiated or terminated. Retained accessory power is controlled by two different methods; relay control and serial data. Some modules receive a retained accessory power message from the BCM over the serial data circuits. Serial data controlled retained accessory power is deactivated as required by their modules retained accessory power mode operation. Other subsystems are activated directly. Components and systems that are active in retained accessory power are also activated anytime the vehicle power mode is any state other than Vehicle OFF regardless of the door switch signals.

Interruptible Retained Accessory Power Relay Controlled Retained Accessory Power

The Keyless entry control module keeps the relay energized during all power modes, except Vehicle Off. The relay is also energized for approximately 10 minutes after moving to the Vehicle OFF state and moving the transmitter out of range, providing no door is opened. The keyless entry control module controls components in

the same manner as BCM direct controlled retained accessory power with one exception; interruptible retained accessory power is deactivated during transmitter authentication. The keyless entry control module will deactivate components that may cause radio frequency (RF) interference when the vehicle On/Off switch is pressed which may result in "NO REMOTE DETECTED" displayed on the driver information center.

Relay controlled retained accessory power will end when one of the following conditions is met:

The keyless entry control module receives a message that any door ajar or open switch indicating the opening of any door after entering the Vehicle Off state and the transmitter is out of range.

NOTE: If the keyless entry control module is receiving any door ajar or open signal from those switches when the Vehicle Off state is entered and the transmitter is out of range, retained accessory power will not initiate.

The keyless entry control module detects a decrease in battery capacity below a prescribed limit.

Systems powered by the retained accessory power relay during the retained accessory power mode are as follows:

Accessory Power Receptacle Cigarette Lighter Receptacle

Serial Data Controlled Retained Accessory Power

Retained accessory power systems controlled by serial data are as follows:

Radio

Radio retained accessory power activation/termination is the same as relay operation with one exception; the only door switch that will turn off the radio during retained accessory power is the driver door open switch.

Vehicle Communication Interface Module (VCIM) (Onstar®) (If Equipped)

VCIM RAP activation/termination is the same as radio operation with 1 exception; if there is an active call when the ignition key is turned off the VCIM will remain in RAP mode, and keep the radio in RAP mode until the call is terminated.

< Назад | Содержимое | Далее >