FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See Section 10; rule 13)
TITLE OF THE INVENTION A system and method for power consumption management in vehicles
APPLICANTS
TATA MOTORS LIMITED, an Indian company
having its registered office at Bombay House,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
INVENTORS
Mr. Ajay Dandge and Mr. Neeraj Sharma
All Indian nationals
working in TATA MOTORS LIMITED,
an Indian company having its registered office
at Bombay House, 24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001 Maharashtra, India
PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed.

Field of The Invention:
The present invention relates to a power consumption management system for vehicles. The present invention also relates to a method of controlling the power consumed by a body control module (BCM) of a vehicle in different operating conditions
Background of the Invention:
Automotive Body control module (BCM) as its name indicate is a central controlling hub for maintaining and controlling different body electrical functions namely, interior and exterior lighting, manual / automated wiping, chiming 8B buzzer indications, central door locking etc. also in many vehicles it acts as a CAN termination node or CAN GATE WAY node. Also this varied functionality handled by BCM has to be operational in vehicle non moving state also which causes battery drains since there is no operation of alternator to charge the battery as it happens in vehicle running condition.
Body control module works in different vehicle operating modes such as ignition OFF, Ignition ON and Crank ON.
Body Control Module (BCM) has been developed to replace discrete controlling components by a means of single electronic control unit to control different accessories of car like Flasher, Fog lamps, Buzzers, Immobilizers, Remote Keyless entry systems etc. Now all these functionalities are controlled by a single unit named BCM i.e. Body Control Module. The advantages of BCM are reduction in wiring, space, maintenance & most importantly in terms of cost.
There is virtually no limit to input and output handled by a typical BCM. The BCM in embodiment here handles around 18 functionalities. To perform

these functionalities there are different input/output ICs, Microcontroller, RF Receiver, Limp-home circuitry etc. on single PCB called as BCM mother board and RF receiver as a separate daughter board.
Due to the necessity of BCM operation during Ignition OFF mode, BCM is expected to draw very less current out of battery so as avoid battery drain. The foremost requirement for BCM operation is to ascertain less current consumption from battery, besides maintaining and performing many tasks like reading switch / sensor inputs, storing data, receiving RF data, controlling the outputs and maintaining the log of specific system errors.
A typical operation carried out by the BCM of a vehicle is activation of RKE module or Central door lock module during vehicle OFF condition.
Because of certain functionalities associated with BCM requiring their operation during vehicle OFF state it is obligatory for BCM to have a mechanism in place to reduce the current drawn by BCM since high current consumption from BCM during vehicle OFF condition might lead to battery drainage leading to loss of functions dependent on battery viz. engine cranking.
Prior publication US 2009/0224869 (US'4869) discloses a system, method and device for monitoring a vehicle wherein a vehicle monitoring device regulates its power consumption of a host power source based upon determined states of operation of the vehicle. However, the disadvantage associated with the system disclosed in (us'4869) is that the power supplied to entire BCM circuit of the monitoring system is not complete turned off during sleep mode of operation of the BCM. Accordingly, the BCM consmes considerable amount of sleep current

Summary of the invention:
Accordingly, the present invention provides a power consumption management system for vehicles comprising a body control module (BCM) and a power supply , said BCM has startup mode, wake-up mode, shutdown mode and low power sleep mode of operation and comprises :
a microcontroller configured to regulate the power consumed by said BCM , said microcontroller is provided with at least a timer module,
input driver modules operatively connected to said microcontroller, said input driver modules comprise input driver circuit and a RF receiver module,
output driver modules operatively connected to said microcontroller,
input/output integrated circuits (ICS), to carry our various functionalities of said BCM,
an input detection circuit for processing BCM inputs and
being operatively connected to said microcontroller and to said
power supply through an input switch interface,
a power supply regulator for regulating the power delivered
from said power supply and being operatively connected with
said microcontroller, said input drivers , said output drivers
and said power supply,
wherein in shutdown mode and in low power sleep mode of said BCM the
microcontroller is configured to detect wakeup signal and interrupt signal
generated from said input driver circuit while maintaining its idle state and
transmit the same to said power supply regulator, and wherein in low power
sleep mode of the BCM said input driver modules, said output driver
modules, said input/output ICS, except the timer modules, are configured
to transit into low power sleep mode upon receiving sleep command from
said microcontroller, and wherein said RF receiver modules are configured
to be alternately switched off and switched on for minimizing the sleep

current consumed by the BCM in low power sleep mode, and wherein said microcontroller generates an inhibit signal to said power supply regulator to cut off the power supplied to the microcontroller when the microcontroller transits from low power sleep mode to low power transport mode.
Preferably, said input driver circuit is operatively connected with said microcontroller and said power supply regulator through an input switch interface and said RF receiver module is operatively connected to said microcontroller and said power supply regulator through a RF input interface. The power supply may be a +5 V DC power supply.
Accordingly to a particular embodiment of the invention said timer module is Real Time Interrupt timer.
In said normal operating mode said BCM, said input drivers, said output drivers and said microcontroller are configured to become active. Preferably, in normal operating mode of the BCM said input driver modules, said output driver modules are initialized, the input/output protocols SPI, SCI, PWM, DIO, PORT are initialized and interrupt service routines are initialized.
If all output loads are turned OFF and the microcontroller of the BCM does not receive any switch inputs or with no communication in progress for prescribed time, it enters into low power sleep mode, an operating mode in which all input and output drivers are put into sleep mode. Also in this mode associated hardware modules inside microcontroller are also disabled in order to lower the microcontroller current consumption.
According to a preferred embodiment of the invented power consumption management system said input detection circuit sends an active high wake-up signal to said power supply regulator when said microcontroller transits

to active mode from low power transport mode. Preferably, the input detection circuit sends active low wake-up signal to said microcontroller when said microcontroller transits to wake-up (active) mode from low power. sleep mode or transport low power mode. The input detection circuit sends active low wake-up signal to said microcontroller upon reception of input transition or valid RF signal. The input detection driver is chosen so as to generate a wakeup signal for power supply regulator (and for microcontroller) for transition from low power transport mode to active moder
According to another preferred embodiment of the invention power consumption management system said input detection circuit sends wake-up signal to said power supply regulator when the microcontroller transits from low power sleep mode or from transport low power mode to wake-up mode. The microcontroller sends inhibit signal to said power supply regulator to cutoff the power supplied to said BCM when the microcontroller transits to low power transport mode. Preferably, said power supply regulator is communicatively connected with said microcontroller and said input driver circuit through a multiplexer circuit. The input detection circuit may send signals to said microcontroller in 8-bit SPI format.
According to a further embodiment of the invented power consumption management system, said microcontroller sends reset signal to said power supply regulator upon detecting low voltage of the power supply. The reset signal generation may also be caused by watchdog runaway.
Preferably, the interrupt signal, generated by said input driver circuit, is transmitted to said microcontroller through an input switch interface; for transiting said microcontroller from low power sleep mode to active mode.

According to another embodiment of the invented power consumption management system said BCM is configured to receive RF signals generated from a microchip keeloq based encoder. The encoder may be HCS301. The HSC301 transmits 66-bit code word and is designed for secure Remote Keyless Entry systems. Preferably, said HCS301 code word contains a 50% duty cycle preamble, a header, 32 bits of encrypted data and 34 bits of fixed data followed by guard period before another code word begin. The preamble time is equivalent to 23 pulse timing element (TE)
Preferably, in the invented power consumption management system said RF signal transmission takes place at 433.92 MHz carrier frequency.
According to a further embodiment of the invented power consumption management system, in low power sleep mode of the microcontroller said RF receiver is turned OFF for 4ms and alternately turned ON for 2 ms. Desirably, when the microcontroller enters low power sleep mode it executes 133 microsecond timer interrupt by counting from high to low, low to high and again high to low transition in order to receive valid RF preamble signal.
According to yet another embodiment of the invented power consumption management system said microcontroller is provided with a limp home watchdog timer IC to monitor microcontroller runaway, said limp home watchdog timer IC is controlled by RTI timer for minimizing the sleep current consumed by the BCM in low power sleep mode.
The present invention also provided a method of controlling the power consumed by a body control module (BCM) of a vehicle comprising the steps of:
monitoring the signals received by input driver modules of said
BCM,
processing BCM input signals through an input detection
circuit of said BCM,

generating control signals from a microcontroller and an input driver circuit of said BCM for regulating the power consumed by said BCM,
receiving the control signal, generated from said microcontroller and/or from said input driver circuit, in power supply regulator of said BCM,
receiving the control signal generated from said microcontroller in output driver modules of said BCM, placing said microcontroller of said BCM in startup mode, wake-up mode , shutdown mode or low power sleep mode depending on the nature of the signal generated from said microcontroller and/or from said input driver circuit.
According to a preferred embodiment of the invented method of controlling the power consumed by a body control module (BCM) of a vehicle said control signals are in the form of an inhibit signal, wake-up signal, interrupt signal or reset signal.
An Inhibit signal is same as wake-up signal generated by input detection
circuit and a similar signal generated by microcontroller to bring power
supply circuit into active mode from low power transport mode.
An active low wake-up signal is a signal from input detection circuit to
power supply circuit to keep it in active mode. An input detection circuit
generates low signal only upon valid input transition, in all other conditions
it is active high indicating input detection circuit sleep mode status.
An Interrupt signal is signal generated by input detection circuit to bring
microcontroller into active mode from low power sleep mode.
A RESET signal is generated by power supply regulator in case low voltage
detection. The RESET signal is generated by power supply circuit to
microcontroller is active low signal.

According to a particular embodiment of the invented method, the microcontroller generates an inhibit signal for putting all input driver modules, all output driver modules, and all input/output ICS of said BCM into low power sleep mode, keeping the timer modules active, before transiting said microcontroller from normal mode to shutdown mode, another inhibit signal for regulating power supply upon non-receipt of any input signal from said input detection circuit and when output driver modules of said BCM become inactive.
Desirably in shutdown mode and in low power sleep mode, the microcontroller is configured to detect wakeup signal and interrupt signal generated from an input driver circuit of said BCM and transmit the same to said power supply regulator, while maintaining said microcontroller in idle state.
According to another embodiment of the invented method said input driver circuit generates interrupt signal for said microcontroller for transiting said microcontroller from low power sleep mode to wake-up (Active) mode. Preferably, the microcontroller of said BCM transmits from low power sleep mode to active mode upon valid input detection by said input detection circuit or upon valid RF preamble detection by a microchip keeloq based encoder, said microchip keeloq based encoder being associated with said BCM.
According to another preferred embodiment of the invented method of controlling the power consumed by a body control module (BCM) of a vehicle, said input driver circuit generates wakeup signal for said microcontroller for transiting the microcontroller from low power transport mode to wake-up mode.

According to a further embodiment of the invented method, said microcontroller generates an inhibit signal directing said power supply regulator to cut off the power supplied to the microcontroller when the microcontroller transits from low power sleep mode to low power transport mode. If low power sleep mode condition persists for more than specific timing of 7 days, microcontroller issues a inhibit signal to power supply regulator to cut off the power supply to microcontroller.
According to yet another embodiment of the invented method, the RF receiver module of said microcontroller is alternately switched OFF and switched ON for minimizing the sleep current consumed by the BCM in low power sleep mode. Preferably, in low power sleep mode of the microcontroller said RF receiver is turned OFF for 4ms and alternately turned ON for 2 ms.
Preferably, said input detection circuit sends wake-up signal to said power supply regulator and to said microcontroller when the BCM transits to wake-up mode from low power sleep mode or from transport low power mode. The microcontroller activates or enables all clock and timing related modules of the BCM before entering into wake up(active) mode from low power sleep mode or from transport low power mode.
According to a particular embodiment of the invented method, said power supply regulator sends a reset signal to said microcontroller upon detecting low voltage of the power supply.
Brief Description of the accompanying drawings:
For better understanding, an illustrative embodiment of the invention will be described with reference to the accompanying drawings. It will however be appreciated that the embodiments exemplified in the drawings is merely illustrative and not limitative to the scope of the invention, because it is

quite possible, indeed often desirable, to introduce a number of variations in the particular embodiment that has been shown in the drawings.
Figure 1 is a schematic diagram illustrates the partial subsystems of a Body Control Module (BCM).
Figure 2 is a schematic diagram of BCM power supply (Control and Regulator circuit) for switching ON/OFF the power supply to Microcontroller.
Figure 3 is block diagram level understanding of power supply system of BCM.
Figure 4 schematically illustrates different signal flow encountered in BCM operation leading to low power mode assertion.
Figure 5 is flow chart representing the broad level flow chart of entire BCM transiting from active to different low power modes.
Figure 6 shows BCM software strategy related to return from Low power mode to Active mode in case any valid RF signal is received.
Figure 7 shows software implementation flow chart of BCM related to power management, this figure typically depicts the software strategy implemented to sense the input signals and output load conditions.
Figure 8 is a schematic diagram showing shows block level hardware implementation of input switch detection and corresponding signal generation to microcontroller and power supply circuit.
Figure 9 shows the valid RF code word format as received by BCM.

Detailed description of the accompanying drawings:
Referring to figure 1 of the accompanying drawing the Body Control Module (BCM) (1) of the invented power consumption management system consists of microcontroller (2), input detection circuitry (3) (not shown in figure 1), output drivers (4) and most importantly a power supply regulator (5). Figure 1 represents basic subsystem blocks of BCM and its interface with each other. Low power mode related BCM block diagram showing limited BCM internal interfaces is as shown in figure 1.
As shown in the figure 1, input received for microcontroller (2) from power supply block is +5V regulated DC voltage. Microcontroller (2) is responsible for sending RESET and inhibits signals to in order to turn OFF power supply to save current consumed by BCM (1). Different conditions for microcontroller to initiate the inhibit command for power supply are discussed subsequently. RESET signal is send by microcontroller (2) caused by watchdog runaway and Low Vdd detection.
Similarly, as shown in figure 8 of the accompanying drawings, microcontroller (2) gets interrupt signal request from Input switch interface system (6) so as to recognize any valid input sequence to change the transition from low power sleep state to active state and vice versa.
The sequence of signal flow to microcontroller and its execution till transport low power mode and return to active mode is shown as in figure 4 of the accompanying drawings.
BCM inputs as processed by input detection circuit (3) is shown figure 8. This circuit sends detection signal to microcontroller (2) for corresponding input in 8-bit SPI format. During sleep low power mode and transport low power mode, wake up signal to microcontroller (2) as send by input

detection circuitry (3) is active high (+5V DC). Upon reception of input transition or valid remote RF data, this signal asserts active low (OV DC), the flow and conditions for generating active low wake up signal to microcontroller is depicted in figure 7 of the accompanying drawings. Wake up signal sent to power supply (7) has been schematically shown in figure 2.
Schematic of power supply (7) has been shown in figure 3 block diagram. The power supply regulator (5) is communicatively connected with said microcontroller (2) and the input driver circuit (8) through a multiplexer circuit (9).
The input driver circuit (8) has been schematically shown in figure 8. Input driver circuit (8) is operatively connected with said microcontroller (1) and said power supply regulator (5) through an input switch interface (10). The RF receiver module is operatively connected to said microcontroller (2) and said power supply regulator (5) through a RF input interface (11).
The REST signal and inhibit signal is received by the inhibit circuit (12) and reset circuit (13) of said power supply regulator (5) while the output power (Vdd) is generated by the regulator circuit (14) of the power supply regulator (5) as shown in figure 3.
During low power sleep mode and transport low power mode this signal is active low (0 to 200mV DC); this signal is asserts active high (normally V batt) with valid input transition.
To take care of all the low power mode actions, all electronic components used in BCM (1) are chosen such a way that overall BCM (1) current consumption will be less, also component chosen are been able to understand and respond to microcontroller command for different sleep modes and active mode.

In order to reduce the current consumed by different peripheral ICs, microcontroller software is designed to receive and process various input and output feedback signal in such a way that during no activity, overall BCM (1) consume less power by virtue of shutting off current consuming output drivers (4), input drivers (8), RF receiver (not shown), power supply (7) and non vital peripheral hardware blocks microcontroller (2), as shown in figure 1.
As shown in figure 2 and 3, power supply regulator (5) also gets wakeup signal from microcontroller (2), subject to requisite conditions being met. Details of the wake us signal generation and functioning of the power supply regulator (5) upon receiving the same has been illustrated figures 4 through 7 and in the below description of microcontroller software, transitioning from active mode to various sleep modes.
To cater different BCM functionalities on vehicle, software execution is divided into different states/modes depending on different input and output signal status. The different modes of the microcontroller (2) has been explained below with reference to figure 1 and 5
1. Startup Mode: In this mode, all driver layer modules like input driver module (not shown), output driver module (4), SPI, SCI, PWM, DIO, PORT (not shown) are initialized, interrupt service routines in this mode are initialized so that it waits for 100ms in order to properly read the analog inputs. After initializing different modules, BCM will switch from Startup Mode to Normal Mode. This sequence is limned as in figure 5.
2. Wakeup/Normal Mode: satisfying the conditions, BCM (1) enters into wakeup or normal mode, in this mode BCM (1) is able to perform or control all or part of intended functions. In this mode call application related module function and based on the inputs, output turns on. In this mode all

fault conditions i.e. Output short to ground/battery, Open wire fault, Over-current etc are monitored detected and are logged. The logged fault conditions can be read through Diagnostic Tool (not shown). This is heavy current usage mode. Current consumed in this mode typically varies from 20mA to 30Ampers, depending on number of outputs turned ON.
3. Shutdown Mode: Pre-requisite for microcontroller (2) software to enter in
shutdown mode is shown in figure 5. Before entering this mode, all driver
layer modules except timer modules (not shown) are made off and all
input/output ICs (not shown) are sent into low power Sleep mode through
Sleep Command from microcontroller (2) software. This is moderate current
usage mode. The current consumed by entire BCM in this mode is
approximately 80mA depending upon battery voltage.
The microcontroller (2) enters into shutdown mode when active control or monitoring of system functions has stopped and microcontroller has become idle again however it must detect certain wake up inputs before entering into wake up state as shown in figure 5 and interrupt signal from input driver circuit (8) as shown in figure 8. The BCM (2) monitors for these wakes up inputs during sleep mode where microcontroller is able to detect any switch transition that causes it to wake up when activated or deactivated. After shutdown mode BCM transits into low power sleep mode as shown in figure 5.
4. Low Power Sleep Mode: for simplicity, description of BCM operation in
this mode is divided into three sub states
a. Low Power Sleep Mode 1: Prerequisite for microcontroller (2) to enter in
this mode are same as shutdown mode; no input signal detection, no output turned on and no K-line or LIN or CAN communication, as is depicted in figure 5. In this state, microcontroller (2) goes into pseudo-stop mode and

microcontroller executes stop instruction, in this mode only RTI timer (not show) is executed. Microcontroller (2) remains in this state for 4ms. After completion of 4 ms, microcontroller (2) transits from Low power Sleep mode 1 to Low power sleep mode 2 as shown in figure 6.
b. Low Power Sleep Mode 2: Microcontroller (2) remains in this state for 2 ms, in this mode; all other software modules are deactivated or disabled except timer module to detect RF Frame preamble and any input transition activity.
As shown in figure 7 and 8, microcontroller (2) must detect certain wake up inputs from input detection circuitry before entering into wake up state. After reception input transition, microcontroller (2) monitors wakeup input typically for 2msec, if switch transition is found to be valid, it causes microcontroller to wake up. With this change microcontroller returns to wake up mode as shown in figure 5. Before going to wake up mode all Clock and timing related modules are activated or enabled by microcontroller (2).
In this mode, if any RF preamble (which is using microchip based keeloq encryption algorithm) is found then microcontroller transits from Low Power Sleep 2 to Low Power Sleep 3 mode. By software design it is customary to return back in low power sleep mode 1 if no valid RF preamble signal or input transition is detected.
As shown in figure 5, return of microcontroller (2) from different Low power sleep mode operations to active mode depends upon successful input detection and valid RF preamble detection. The sequence of RF preamble detection is illustrated as follows.
Microcontroller software in said BCM (1) is designed to receive RF signals from Microchip keeloq based encoders. Typically HCS301 encoder is used

for signal transmission. It is a code hopping encoder designed for secure Remote Keyless Entry (RKE) systems. The signal transmission takes place at 433.92MHz carrier frequency. HCS301 transmits a 66-bit code word when any remote button is pressed. The 66-bit word is constructed from a Fixed Code portion and an Encrypted Code portion as shown in figure 9. This figure is from the datasheet of HCS301 from Microchip Technology Inc.
To reduce current consumed by RF Receiver (not shown) in Low Power Sleep modes, RF receiver is turned OFF for 4ms and turned ON for 2 ms. The ON/OFF timing chosen is sufficient to detect valid permeable RF signal. As per HCS301 encoder data sheet, The HCS301 code word is made up of several part as shown in figure 9. Each code word contains a 50% duty cycle preamble, a header, 32 bits of encrypted data and 34 bits of fixed data followed by guard period before another code word begin,
As shown in figure 9., preamble time is equivalent to 23 TE where TE is pulse timing element, as per HCS301 data sheet, typical value of TE is 400 microsecond with maximum and minimum values being 660 microsecond and 260 microsecond respectively. To receive preamble part, 133 microsecond timer interrupt is executed in microcontroller which counts from high to low, low to high and again high to low transion. Three transitions are sufficient to find out valid preamble considering the maximum possible value of TE i.e. 3 *660us = 1.98ms.
With 1.98ms being the maximum time to receive 3 valid transition signals, the selection of 2mS ON time is justified making sure that in any case within 2ms timing valid preamble pulse will be successfully detected and no valid RF preamble signal will be missed. After detection of valid RF preamble signal BCM transits from Low Power sleep mode 2 to Low power sleep mode 3 state.

c. Low Power Sleep Mode 3: In this operating mode, microcontroller (2) receives complete RF signal frame, this frame is decoded for validity. As shown in figure 6, RF signal frame received is valid then only microcontroller transits from Low Power Sleep Mode 3 to wake up state otherwise returns back to Low Power Sleep Mode 1 state. In mode 3, 133 us timer module and RF related modules are activated rest of the modules are deactivated or disabled to maintain sleep current as much as low as shown in table 1. If any valid remote signal is detected then only all other modules are activated or enabled by microcontroller before entering into wake-up Mode.

BCM Operating Mode Current consumed % of Total current
(@Vbatt=12VDC) consumed by BCM
Active Mode (no outputs turned 70mA 100
ON)
Active Mode (some or all outputs 150mA to 24A
turned ON)
Low Power Sleep Mode 1 6mA 9
Low Power Sleep Mode 2 6 mA 9
Low Power Sleep Mode 3 11mA 14
Low Power Transport Mode 0.2 mA <1
Table 1. Summary of Current Consumed by BCM in Various Operating
Mode. If sleep mode condition persists for more than specific configurable timing of 7 days, microcontroller issues a inhibit signal to power supply regulator to cut off the power supply to microcontroller. This mode is called as Low Power transport mode.
5. Low Power Transport Mode: Figure 5 illustrates the transition of BCM from Low power sleep mode to low power transport mode. Low power

Transport mode is also termed as FULL-Stop Mode of microcontroller in microcontroller firmware terminology. In this operating mode +5V DC power is disabled in the BCM by placing power supply circuit to OFF condition through INHIBIT signal from Microcontroller. Being no +5V DC power supply, current consumed by RF receiver, input drivers, output drivers and microcontroller is brought down to as low as few micro amperes. The reassertion of wake up mode from Low power transport mode is as depicted in figure 5.
The timing selected to monitor limp home mode circuit is 4msec OFF and 2msec ON of logic high signal type, signal with timing is feed to limp home watchdog timer IC to monitor microcontroller runaway. This timing signal is sent by microcontroller in wake up mode, Low Power Sleep mode 1 and Low power sleep mode 2 operation of BCM.
As already mentioned, the foregoing description is illustrative of the invention and not limitative to its scope, because it will be apparent to persons skilled in the art to devise other alternative embodiments without departing from the broad ambit of the disclosures made herein.
ACRONYMS:
BCM - Body control Module
RF- Radio Frequency
ms - mili seconds
us - micro second
mA - mili ampere
LIN- Linear Interconnect Network
CAN - Control Area Network
RKE -Remote Keyless Entry
RTI - Real Time Interrupt
SPI - Serial Peripheral Interface
SCI - Serial Communication Interface

We claim:
1. A power consumption management system for vehicles comprising a body control module (BCM) and a power supply , said BCM has startup mode, wake-up mode, shutdown mode and low power sleep mode of operation and comprises :
- a microcontroller configured to regulate the power consumed by said BCM , said microcontroller is provided with at least a timer module,
- input driver modules operatively connected to said microcontroller, said input driver modules comprise input driver circuit and a RF receiver module,
- output driver modules operatively connected to said microcontroller,
- input/output integrated circuits (ICs), to carry our various functionalities of said BCM,
- an input detection circuit for processing BCM inputs and being operatively connected to said microcontroller and to said power supply through an input switch interface,
- a power supply regulator for regulating the power delivered from said power supply and being operatively connected with said microcontroller, said input drivers , said output drivers and said power supply,
wherein in shutdown mode and in low power sleep mode of said BCM the microcontroller is configured to detect wakeup signal and interrupt signal generated from said input driver circuit while maintaining its idle state and transmit the same to said power supply regulator, and wherein in low power sleep mode of the BCM said input driver modules, said output driver modules, said input/output ICS, are configured to transit into low power sleep mode upon receiving sleep command from said microcontroller, and wherein said RF receiver modules are configured to be alternately switched off and switched on for minimizing the sleep current consumed by the BCM

in low power sleep mode, and wherein said microcontroller generates an inhibit signal to said power supply regulator to cut off the power supplied to the microcontroller when the microcontroller transits from low power sleep mode to low power transport mode.
2. The power consumption management system for vehicles, as claimed in claim 1, wherein said timer module is Real Time Interrupt timer.
3. The power consumption management system as claimed in any one of preceding claims , wherein in normal operating mode of the BCM said input driver modules, said output driver modules are initialized, the current consuming input/output hardware modules inside microcontroller like SPI, SCI, PWM, DIO/PORT are initialized and interrupt service routines are initialized.
4. The power consumption management system as claimed in any one of the preceding claims, wherein said input detection circuit sends an active high wake-up signal to said power supply regulator when said microcontroller transits to active mode from low power transport mode or from low power sleep mode.
5. The power consumption management system as claimed in any one of the preceding claims, wherein said input detection circuit sends active low interrupt signal to said microcontroller when said microcontroller transits to wake-up mode from low power sleep mode or transport low power mode.
6. The power consumption management system as claimed in any one of the preceding claims, wherein said power supply regulator is communicatively connected with said microcontroller and said input driver circuit through a multiplexer circuit.

7. The power consumption management system as claimed in any one of the preceding claims, wherein in low power sleep mode of the microcontroller said RF receiver is turned OFF for 4ms and alternately turned ON for 2 ms.
8. The power consumption management system as claimed in any one of the preceding claims, wherein in low power sleep mode said microcontroller executes 133 microsecond timer interrupt by counting from high to low, low to high and again high to low transition in order to receive valid RF preamble signal.
9. A method of controlling the power consumed by a body control module (BCM) of a vehicle comprising the steps of :

- monitoring the signals received by input driver modules of said BCM,
- processing BCM input signals through an input detection circuit of said BCM,
- generating control signals from a microcontroller and an input driver circuit of said BCM for regulating the power consumed by said BCM,
- receiving the control signal, generated from said microcontroller and/or from said input driver circuit, in power supply regulator of said BCM,
- receiving the control signal generated from said microcontroller in output driver modules of said BCM,
- placing said microcontroller of said BCM in startup mode, wake-up mode , shutdown mode or low power sleep mode depending on the nature of the signal generated from said microcontroller and/or from said input driver circuit.

10. The method of controlling the power consumed by a body control module (BCM) of a vehicle as claimed in claim 9, wherein said control signals are in the form of an inhibit signal for putting all input driver modules, all output driver modules, and all input/output ICS of said BCM into low power sleep mode, keeping the timer modules active, before transiting said microcontroller from normal mode to shutdown mode, another inhibit signal for regulating power supply upon non-receipt of any input signal from said input detection circuit and when output driver modules of said BCM become inactive..
11. The method of controlling the power consumed by a body control module (BCM) of a vehicle as claimed in any of claims 9 to 10, wherein in shutdown mode and in low power sleep mode the microcontroller is configured to detect wakeup signal and interrupt signal generated from an input driver circuit of said BCM and transmit the same to said power supply regulator, while maintaining said microcontroller in idle state.
12. The method of controlling the power consumed by a body control module (BCM) of a vehicle as claimed in any of claims 9 to 11, wherein the microcontroller of said BCM transmits from low power sleep mode to active mode upon valid input detection by said input detection circuit or upon valid RF preamble detection by a microchip keeloq based encoder, said microchip keeloq based encoder being associated with said BCM.
13. The method of controlling the power consumed by a body control module (BCM) of a vehicle as claimed in any of claims 9 to 12, wherein said input driver circuit generates wakeup signal for said microcontroller for transiting the microcontroller from low power transport mode to wake-up mode.

14. The method of controlling the power consumed by a body control module (BCM) of a vehicle as claimed in any of claim 9 to 13, wherein RF receiver module of said microcontroller is alternately switched OFF for 4ms and switched ON for 2ms for minimizing the sleep current consumed by the BCM in low power sleep mode.
15. The method of controlling the power consumed by a body control module (BCM) of a vehicle as claimed in any of claims 9 to 14, wherein said input detection circuit sends wake-up signal to said power supply regulator and to said microcontroller when the BCM transits to wake-up mode from low power sleep mode or from transport low power mode.