GM3 BCU V10 (SM042V10)

GM3 BCU V10 - System Overview

Borrowed directly from BMW, as the most suitable ECU to modify for the L322 Range Rover application, the GM3 BCU is one in a series of GM variations which controls a large number of different systems throughout the vehicle such as Alarms & Locking, Doors & windows, Wipers and washers.

SM042 - GM3 BCU V10 - System Help file

Version 1.27

GM3 BCU - Known Fitments

Vehicle makes, models and variants known or believed to be using this vehicle system, required diagnostic lead and degree of known compatibility.

Vehicle Make	Vehicle Model	Vehicle Variant	Diagnostic Lead
Land Rover	Range Rover MK III ( L322)	2002 - 2009	Black OBDII Lead/LD020/LD021

GM3 BCU - Physical Details

SM042 - GM3 BCU - Diagnostic Capabilities (Read Fault Codes)

Reads the fault code memory. The ECU can self detect over 140 different problems with itself, its wiring and its associated sensors, storing the respective code if it detects any malfunction or reading outside of pre defined acceptable limits. Not all stored faults may cause the fault warning lamp to illuminate.

SM042 - GM3 BCU - Diagnostic Capabilities (Clear Fault Codes)

Clears the fault code memory.

SM042 - GM3 BCU - Diagnostic Capabilities (Settings)

Values, configuration settings, and other stored information which can be read from the ECU, edited and then rewritten back. Read settings can also be stored as a standard HTML page for reference. These pages can then later be re loaded and re written back to the ECU. Please note that some values may be read only due to the fact that they are supplied from the ECU’s ROM or are internally calculated.

Part Number: This is the manufacturer's part number for the ECU.
Hardware number: This is the hardware version which denotes the processor and circuit board type.
Software number: This is a number which relates to the software programmed in the processor of the ECU.
Supplier number: This is a number which defines the supplier using a standard look up list of supplier of ECU manufacturer.
Coding index: This is a number which denotes the layout of the options within the EEPROM of the ECU and denotes which coding map should be used to program the ECU with.
Diagnostic index: This is a number that indicates the diagnostic capabilities support level.
Bus index: This is a number that indicates the bus communication support level, the vehicle communication buses.
Week of build: This is the week of the year in which the unit was built.
Year of build: This is the year in which the unit was built.
Intensive Wash: Front windscreen intensive wash program, normally disabled on a Range Rover.
Headlamp Power Wash: Denotes if the headlamp power wash is fitted or not fitted.
Special Wash Function: Denotes if the special washing function is enabled or disabled, normally disabled on a Range Rover. This function is available only for E53 BMW.
Headlamp Cleaning: Denotes if the headlamp cleaning is active or not, normally disabled on a Range Rover.
Visual Entry Configuration: This is the configuration of the visual entry, not applicable for Range Rover. Default value for Range Rover is 238.
Folding Mirrors: This denotes if the electric folding mirrors are fitted or not fitted.
Heated Mirrors: This denotes if the heated mirrors are fitted or not fitted.
Memory Mirrors: This denotes if the memory for the outside mirrors is either enabled or disabled.
Electric Rear Windows: This denotes if the electric rear windows are enabled or disabled.
Interior Lamp Configuration: This is the configuration of the interior lamp, default value for Range Rover is 238.
Steering Column Memory: This denotes if the steering column position is either enabled or disabled.
Visual Entry: This denotes if the visual entry is enabled or disabled. This feature is available only for BMW, normally disabled on a Range Rover.
On Board Computer Immobilisation: Status of the on board computer enabled or disabled - normally disabled.
Interior Lights: When enabled, it caused the interior lights to fade in when turned on and when turned off to fade off.
Rain Sensor: This denotes if the rain sensor is fitted or not.
Hydraulic Lift Gate Pressure Control: This denotes if hydraulic lift gate pressure control is is active or inactive. This feature is not avilable for Range Raver.
Hydraulic Lift Gate: This is a function for usage on vehicles supplied with hydraulic boot opening capabilities obviously not the Range Rover.
Interior Lights With Tailgate: This function sets the body control to allow the interior lights to stay on when that tailgate is open. This function is inabled for Range Rover.
Fold Away Rain Sensor: This function sets the body control to allow the wipers to park verically. Set inactive for vehicles with fold away and active for vehicle without fold away like Range Rover.
Wiper Interval At Standstill: The wiper interval can be set to either 3 or 5 seconds.
Wiper Speed Step-down At Standstill: If enabled, the wiper will slow down at standstill. Normally this is disabled if a rain sensor is fitted.
Timer Rear Window: This function is available only when the electric rear window is enabled and it gives an 8 second protection in case of mechanical error.
Driver's Memory Seat: This denotes if Driver's memory seat are fitted or not.
Passenger's Memory Seat: This denotes if Driver's memory seat are fitted or not.
Front switch block: This denotes if front switch built in block is fitted or not
Key Memory: This denotes if key identification that is sent on the K-BUS is active or inactive, normally active in a Range Rover. Enabled allows settings to be stored for individual keys
K-BUS Delay 300ms: This denotes if 300 miliseconds delay on K-BUS is active or not, normally active in a Range Rover.
P-BUS Delay 300ms: This denotes if 300 miliseconds delay on P-BUS is active or not, normally active in a Range Rover.
Single Point Eentry Key 1: This denotes if single point entry for key 1 is enabled or disabled. This feature is available only if key memory is enabled.
Single Point Eentry Key 2: This denotes if single point entry for key 2 is enabled or disabled. This feature is available only if key memory is enabled.
Single Point Eentry Key 3: This denotes if single point entry for key 3 is enabled or disabled. This feature is available only if key memory is enabled.
Single Point Eentry Key 4: This denotes if single point entry for key 4 is enabled or disabled. This feature is available only if key memory is enabled.
1 Touch Windows Disabled with Door Open: When the door is open it disables this feature. This function is disabled on a Range Rover.
Automatic Locking Key 1: This performs automatic self locking of the vehicle if the vehicle exceeds the speed as dictated in the speed locking speed value when key 1 is used.
Automatic Locking Key 2: This performs automatic self locking of the vehicle if the vehicle exceeds the speed as dictated in the speed locking speed value when key 2 is used.
Automatic Locking Key 3: This performs automatic self locking of the vehicle if the vehicle exceeds the speed as dictated in the speed locking speed value when key 3 is used.
Automatic Locking Key 4: This performs automatic self locking of the vehicle if the vehicle exceeds the speed as dictated in the speed locking speed value when key 4 is used.
Driver's Window 1 Touch Close: enabled or disabled - When enabled, it allows the window to be closed with one touch letting go. When disabled, it operates in dead mans handle mode with the button being continuously pressed for the window to keep moving. This feature is valid only if anti trap reverse is set as long.
Driver's Window 1 Touch Open: enabled or disabled - When enabled, it allows the window to be opened with one touch letting go. When disabled, it operates in dead mans handle mode with the button being continuously pressed for the window to keep moving.
Passenger's Window 1 Touch Close: enabled or disabled - When enabled, it allows the window to be closed with one touch letting go. When disabled, it operates in dead mans handle mode with the button being continuously pressed for the window to keep moving. This feature is valid only if anti trap reverse is set as long.
Passenger's Window 1 Touch Open: enabled or disabled - When enabled, it allows the window to be opened with one touch letting go. When disabled, it operates in dead mans handle mode with the button being continuously pressed for the window to keep moving.
Rear Windows 1 Touch Close: enabled or disabled - When enabled, it allows the window to be closed with one touch letting go. When disabled, it operates in dead mans handle mode with the button being continuously pressed for the window to keep moving. This feature is valid only if anti trap reverse is set as long.
Rear Windows 1 Touch Open: enabled or disabled - When enabled, it allows the window to be opened with one touch letting go. When disabled, it operates in dead mans handle mode with the button being continuously pressed for the window to keep moving.
Sunroof 1 Touch Close: enabled or disabled - When enabled, it allows the sunroof to be closed with one touch letting go. When disabled, it operates in dead mans handle mode with the button being continuously pressed for the sunroof to keep moving.
Sunroof 1 Touch Open: enabled or disabled - When enabled, it allows the sunroof to be opened with one touch letting go. When disabled, it operates in dead mans handle mode with the button being continuously pressed for the sunroof to keep moving.
CDL Removes Superlock: When enabled, unlocking using the centre unlocking button unlocks it even in superlocked mode.
Anti Trap Reversing: This is the distance the windows reverse when detecting a trap condition and it can be set to either short or long.
Lazy Unlock with Key: When enabled, this allows the user to use the key in the door lock to wind down the windows.
Lazy Lock with Key: When enabled, this allows the user to wind up the windows when locking the car with the key.
Auto Relock After Two Minutes: When enabled, if the vehicle is unlocked using the remote control and there are no doors or tailgate opened, after two minutes the vehicle will relock but not superlock. The alarm will not be rearmed.
Unlock if Ignition on 30 Seconds After Locking: When enabled, if the ignition is turned on within 30 seconds of locking the doors the locks will unlock.
Unlock with Key if Armed: When enabled, unlocking using the door key is enabled even if the alarm is still armed.
Tailgate Lock with Ignition On: When enabled, allows the tailgate to be locked when the ignition is on. It will have effect only if center button crash is set to active.
Tailgate Release 10s fter Crash: When enabled, allows the tailgate to be released in case of crash after 10 seconds.
Remote Lazy Unlock: When enabled, it allows the user to unlock/wind the window down using the remote control.
Remote Lazy Lock: When enabled, it allows the user to lock/wind the window up using the remote control.
Alarm: The body controls alarm system, either enabled or disabled. Alar LED is active for 10 seconds in the disabled mode
Volumetric Sensor: Enabled or disabled, depending on whether a volumetric sensor is fitted or not.
Tilt Sensor: Enabled or disabled, depending on whether a tilt sensor is fitted or not.
Remote Arming/Disarming: The options are either the remote control only is capable of arming/disarming the alarm, or both key and remote are capable of arming/disarming the alarm.
Alarm Sound: The sound of the alarm, either continuous or intermittent.
Main Beam on Alarm: When the alarm has been triggered, the main beams are used if set to enabled. If set to disabled, the main beam will be not used.
Dip Beam on Alarm: When the alarm has been triggered, the dip beams are used if set to enabled. If set to disabled, the dip beam will be not used.
Hazard on Alarm: When the vehicle has been triggered, the hazards are only used if set to enabled. If set to disabled, the hazards will be not used.
Alarm Arm Acknowledge with Hazards: When enabled, arming the alarm will produce a single flash on the hazards.
Alarm Arm Acknowledge with Horn/Siren: When enabled, this will cause the alarm arm to make a beep on the horn or siren.
Alarm Disarm Acknowledge with Hazards: When enabled, disarming the alarm will produce a single flash on the hazards.
Alarm Disarm Acknowledge with Horn/Siren: When enabled, this will cause the alarm disarm to make a beep on the horn or siren.
Alarm Acknowledge Beep Time Length: This is a value selectable in 10 millisecond increments from 0 to 150 milliseconds, normally set to 80 milliseconds.
Interior Light on Repeated Lock Requests: When enabled, the interior lights illuminate with every press on the lock button on the remote or by key.
Alarm Repeats if Trigger Still There: When enabled, the trigger of an alarm if it is still present will cause the alarm to continually re-trigger, otherwise it will trigger just once.
Interior Light on in Crash: When enabled, the interior lights illuminate in case of crash only at stand still.
Alarm Trigger - Tyre Pressure & Taigate: When enabled, the trigger of an alarm will cause changes in the tyre pressure and tailgate. This should be set as disabled for a Range Rover.
Alarm Trigger - Tyre Pressure on K-BUS: When enabled, the trigger of an alarm will cause changes in the tyre pressure on the K-BUS. This should be set as disabled for a Range Rover.
IR Remote On Passengers Door: This denotes if the infra red remote on passenger's door is enabled or disabled.
BBUS: The battery back up sounder - either fitted or not fitted.
Automatic Immobilisation: This causes the engine to automatically immobilise after a set period of time.
Alarm Acknoledge When all Panels Closed: This enables or disables alarm arm acknowledgement only when all doors, lids, bonnet are closed.
Center Lock in Crash: This enables or disables locking via cehter lock button in crash mode.
Rear Volumetric Sensor: This function is enabled when an additional volumetric sensor is fitted in the rear.
Driver's Front Window Anti Trap Monitoring: This enables or disables the anti trap function for this window.
Driver's Rear Window Anti Trap Monitoring: This enables or disables the anti trap function for this window.
Passenger's Front Window Anti Trap Monitoring: This enables or disables the anti trap function for this window.
Passenger's Rear Window Anti Trap Monitoring: This enables or disables the anti trap function for this window.
Tailgate Window Anti Trap Monitoring: This is normally disabled on the Range Rover because it does not have an electric opening/closing tailgate window fitted.
Periphery Sunroof: This denotes if the sunroof is either fitted or not fitted.
Glass Sunroof: This denotes if the sunroof is either fitted or not fitted.
Window Timer Configuration Type: This is a value which configures the conditions under which the window timer times out. In some markets it times out as soon as the ignition is turned off and in other markets when the driver's door is opened. Normally it is set to 1 in all markets for the Range Rover.
Rear Volumetric Sensor: This function is enabled when an additional volumetric sensor is fitted in the rear.
Front Door Ajar Input Via: Direct input means that is straight from the switch to the body control module. Outstation is via an external door control unit.
Central Locking Type: Range Rover or other can be selected.
CDL Barrel Front Passenger Door: This is normally set to enabled whenever a passenger door key barrel is not fitted.
CDL Hotel Position: This is normally set to enabled whenever a passenger door key barrel is not fitted. Tailgate opening is disabled from the centre control switch and tailgate cylinder lock - not fitted in Range Rover.
Autolock Disable: Enable or Disable automatic locking.
Tailgate Disarm: Enable or Disable disarm via tailgate.
Automatic CDL Disabled when Using Centre Switch: Enable or Disable speed lock.
Superlock Disabled when Using Centre Switch: This feature permits superlock disable when vehicle is armed.
Selective CDL: If Key Memory is enabled, this setting will be ignored. If key memory is disabled, it can enable or disable sngle entry for all keys.
Autolock Speed: This is the speed in km when the autolock gets activated. Valid valuea are betwwn 0 and 56.
Trigger Delay for Panic Mode: This is the amount of time the user has to press the remote control tailgate button before the panic mode is engaged where the alarm, siren and illumination activates if set by that feature. This is a value between 0 and 3 seconds.
Number of Engine Cylinders: This is the number of engine cylinders.
K Bus Remote: When enabled, remote control functions are transmitted via the K Bus. This should be set to disabled as K-Bus is not longer used and the remote signal is sent direct to the body control ECU.
Inhibit Time After Ignition Off: This is a the period of time the remote control cannot be used after the ignition has been switched off. This is a numerical value between 0 and 3 seconds.
Debounce Time for Crash Sensors: This is the debounce time for crash sensors. This is a numerical value between 0 and 255, default value for Range Rover being 100.
Vehicle Type: This is the vehicle type.
Servotronic: This is the speed related power steering sensitivity system, enabled or disabled, normally enabled on a Range Rover.
Servotronic Mapping via ABS: Enable or disable the vehicle speed signal from servotronic to be transmitted via ABS. Set as enabled for Range Rover.
Servotronic Map Source: ROM or EPROM - EPROM is used for the New Range Rover. The value it is set in the mapping section.
Servotronic Code: This is the servotronic code number. Default value for Range Rover is 0.
Door Contact Logic: This either ensures a door is closed or open, monitoring the contact when the door is closed.
Panic Alarm: The panic alarm is a function where pressing and holding the tailgate to unlock button, the alarm sounds and the hazards warning lamps flash according to their settings.
Wiper Pressure Adaption: Wiper pressure adaption to windscreen used only on BMW. This should be set to disabled in a Range Rover.
Passive Horn: enabled or disabled the passive horn. It will have influence over the BBUS.
DWA on pin 17: enabled or disabled - when enabled will allow the BBUS to be set as enabled or dasabled and enable disable of arming acknolidge with hazards.
VA_2: Feature available only on BMW, this should be set inactive in a Range Rover.
Vehicle Options Programmed Flag: This flag must be set on new ECUs to the programmed as opposed to the not programmed option. This indicates to the body control unit that the entire vehicle's options memory is actually valid data as opposed to zeros on a blank ECU.

MAPPING

Servotronic Speed Map: These values are hexadecimal bytes which set up the speed map for the servotronic with default values for Range Rover of: 00, 02 ,0A, 14, 1E, 28, 32, 3C, 46, 50, 5A, 6E, 82, 96, A0, FA. These values must be separated by commas.
Servotronic Speed Map Programmed Flag: This must be set to programmed for the servotronic speed map to be recognised.
Servotronic Current Map: These values are hexadecimal bytes which set up the speed map for the servotronic with default values for Range Rover of: F3, BF, AC, A3, 9A, 92, 8B, 83, 7A, 74, 6E, 5F, 4C, 38, 2D, 1D. These values must be separated by commas.
Servotronic Current Map Programmed Flag: This should be set to programmed as opposed to not programmed to indicate that the servotronic map is current valid data.
Coding Data: A specific block of programmable data stored in the ECU to control its functionality for specific variations of vehicle. There are a number of hexadecimal digits, each digit separated by a comma. Re-entered parameters should be entered in an identical format to that which is read. Changing this values can produce unknown alteration in the functionality of the ECU, damage the ECU, or even damage your car.

SM042 - GM3 BCU - Diagnostic Capabilities (Inputs)

Realtime live display of the information the electronic control unit of the selected vehicle system is currently deriving from its input sensors.

Tailgate Ajar: This shows the current status of the tailgate: open or closed.
Dashboard Mounted Tailgate Release Switch: This shows if the button is pressed or not.
Lower Tailgate Release Switch: This shows if the button on the lower tailgate has been released or not.
Upper Tailgate Release Switch: This shows if the button on the upper tailgate has been released or not.
Bonnet: This shows if the bonnet is closed or not.
Driver's Front Door Ajar: This shows if the driver's door is open or closed.
Passenger's Front Door Ajar: This shows if the passenger's door is open or closed.
Rear Passenger Side Door Ajar: This shows if the rear passenger's side door is open or closed.
Rear Driver Side Door Ajar: This shows if the rear driver's side door is open or closed.
Rear Driver's Door Window Switch: This shows the current position of the rear driver's door window switch.
Rear Passenger's Door Window Switch: This shows the current position of the rear passenger door window switch.
Passenger's Door Window Switch: This shows the current position of the passenger's door window switch.
Manual Central Locking Switch: This shows if the button is pressed or not.

DRIVER'S DOOR SWITCH PANEL

Driver's Window Switch: This shows the current position of the driver's door window switch for the driver's door.
Rear Driver Window Switch: This shows the status of the driver's door mounted rear driver window switch.
Rear Passenger Window Switch: This shows the status of the rear passenger's window switch mounted on the driver's door.
Passenger's Window Switch: This shows the current position of the driver's door mounted passenger window switch.
Mirror Switch: This shows the current direction of the mirror direction switch.
Mirror Select: This shows if the mirror switch is selected to passenger's side or driver's side.
Power Fold: This shows if the mirror power fold button is pressed or released.
Rear Window Disable Switch: This shows if the rear window disable switch is on or off.

OTHER

Wiper Switch: This shows if the wipers are on or off.
Intermittent Speed Wipers Switch: This shows if the current selection for the intermittent speed as a numerical value.
Windscreen Wash Switch: This shows if the windscreen wash button is pressed or not.
Wiper Park: This shows if the wiper is in park position or not.
Any Signal Received: This shows if a signal of the correct frequency is being received.
Key Signal Received: This shows if a signal of the correct frequency for the correct key is being received.
Last Key Used: This shows the number of the key last accepted.
Key 1 Battery Status: This shows the current status of the battery in Key 1.
Key 2 Battery Status: This shows the current status of the battery in Key 2.
Key 3 Battery Status: This shows the current status of the battery in Key 3.
Key 4 Battery Status: This shows the current status of the battery in Key 4.
Driver's Door Anti Trap Strip: This shows the input of the anti trap strip mounted at the top of the window of the driver's door.
Passenger's Door Anti Trap Strip: This shows the input of the anti trap strip mounted at the top of the window of the passenger's door.
Rear Driver's Door Anti Trap Strip: This shows the input of the anti trap strip mounted at the top of the window of the rear driver's door.
Rear Passenger's Door Anti Trap Strip: This shows the input of the anti trap strip mounted at the top of the window of the rear left passenger's door.
Interior Light: This shows if the interior light button is pressed or released.
Sunroof Switch: This shows the current status of the sun roof switch.
Sunroof Position: This shows if the sun roof is open or closed.
Servotronic PWM %: This shows the current percentage value of the servotronic server motor output.
Servotronic current mA: This shows the power steering servo valve current measured in mA.
Transmitter Tailgate Button: This shows that if the button on the key fob in use is pressed for the tailgate.
Transmitter Lock/Unlock Button: This shows if the button on the key being used is being pressed for the Lock or Unlock.
Driver's Door Unlock: This shows if the key is being turned to the unlock position.
Driver's Door Lock: This shows if the key is being turned to the lock position.

SM042 - GM3 BCU - Diagnostic Capabilities (Outputs)

A selection of functions and outputs that can be tested. Each output has the option ON and OFF in order to start and stop testing. BECU has control over the following features:

DOORS AND LOCKING

Warning: leaving the locking solenoids energized (on) for more then a few seconds can result in their being permanently damaged.
Upper Tailgate Release: Turn the upper tailgate release solenoid ON or OFF.
Lower Tailgate Release: Turn the lower tailgate release solenoid ON or OFF.
Rear Doors Lock: Turn the rear doors lock solenoid ON or OFF.
Rear Doors Unlock: Turn the rear doors unlock solenoid ON or OFF.
Rear Doors Secure Lock (Superlock): Turn the rear doors secure lock solenoid ON or OFF. This will superlock the rear doors.
Driver's Door Lock: Turn the driver's doors lock solenoid ON or OFF.
Driver's Door Unlock: Turn the driver's doors unlock solenoid ON or OFF.
Driver's Door Secure Lock (Superlock): Turn the driver's doors secure lock solenoid ON or OFF. This will superlock the driver's door.
Passenger's Door Lock: Turn the passenger's doors lock solenoid ON or OFF.
Passenger's Door Unlock: Turn the passenger's doors unlock solenoid ON or OFF.
Passenger's Door Secure Lock (Superlock): Turn the passenger's doors secure lock solenoid ON or OFF. This will superlock the passenger's door.

WINDOWS

Windows: All four windows can be opened and closed. Click on ON to start the movement, and on OFF to stop it.
Caution: make sure that nothing obstructs the window. With the anti trap on, the window should stop winding up when detects an obstruction.
Wipers and Washers: Tests the wipers and washers for the windscreen and headlamp.
Alarm: tests the alarm and alarm's LED.
Driver's Mirror: Possibility to move the driver's mirror up, down. left, right, fold in fold out, or the mirror heater.
Passenger's Mirror: Possibility to move the driver's mirror up, down. left, right, fold in fold out, or the mirror heater.

SM042 - GM3 BCU - Diagnostic Capabilities (Other)

Choice of functions that can be performed.

Read Transport Mode: This allows the current transportation mode to be verified.
Set Transportation Mode: This allows the transportation mode to be set. Make sure that the vehicle is not central locked or super locked. By setting the body control in transport mode, the ECU will store a fault. where the vehicle will no longer adjust its height.
Clear Transport Mode: This allows the transport mode lock to be cleared. Make sure that the vehicle is not central locked or super locked. Clearing the transport mode will not clear the fault code in the BCU memory. As long as the faul remain in the memory, the ECU will be reported as in transport mode.