SM134 - DISCOVERY 4 (LR4) - System Overview |
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| The
electronics of the Discovery Series 4, also known as LR4 in the USA and
code named L319 are comprised of around 25 separate ECU’s (nodes) which
are all interconnected by high speed communication Busses. This allows
them to interact with each other at high levels of interdependency,
sharing information vital to their operation. A fault in any one ECU or
its removal often has knock on effects in the others, with them storing
bus error or missing node fault codes.
Most of the ECU’s use either a High speed (500K) or Medium speed (125K)
CAN bus, which are both wired to the Diagnostic socket, these are also
interconnected by the Instrument pack which acts as a built in gateway
between the two busses. However the ECU’s related to information or
entertainment that might additionally have to exchange Video or Audio
data use a special fibre optic bus called the MOST bus. This bus is not
connected to the diagnostic socket but is connected to the Medium speed
CAN bus through the main Audio Head Unit which again acts as a gateway.
High line or Low Line Audio The Discovery 4 has 2 options for Audio equipment most noted by the head unit in the centre of the dash board. The High Line Audio head unit has a 3 x 4 button matrix immediately to the left of it's LCD display panel and the Low Line audio head unit has a row of 6 buttons underneath it's LCD display panel.
High line or Low Line Instrument Pack
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SM134 - DISCOVERY 4 (LR4) - Known Fitments |
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Vehicle
makes, models and variants known or believed to be using this vehicle
system, required diagnostic lead and degree of known compatibility.
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SM134 - DISCOVERY 4 (LR4) - Physical Details |
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SM134 - DISCOVERY 4 (LR4) - Diagnostic Capabilities (Read Fault Codes) |
The Reading Fault codes ability of this software module is also supported by the Stand Alone Diagnostic capabilities of the Faultmate MSV-2 Extreme. In some cases Abbreviations are used to save space on the LCD display of the EXTREME, in which case the abbreviation we use is shown in capitals within square brackets [LIKE THIS]
The functionality of each of this vehicles ECU's in respect of its strategy / methodology for detecting, recording and reporting faults follows the format of a new and very advanced industry standard known as ISO 14229. It is one of the very first vehicles to support this new standard and as such not all ECU's fully support all its features or get it exactly right. It therefore requires some understanding to use and interpret correctly, but is far more informative and helpful in helping properly fix any problem in a vehicle. The ISO 14229 standard defines Fault codes, which it calls DTC's (Diagnostic Trouble Codes) as 2 byte code values / meanings (up to 65536 possibilities). These translate to a 5 digit codes that are prefixed with a letter, P, B, U, C that groups each fault respectively into Powertrain, Body, Chassis and Network related. These 2 Byte code meanings are by definition quite basic with a third byte then being used to provide additional further detail in the form of a lookup of nearly 100 possible fault causes of 256 possible, EG open circuit, Short to Battery, Out of Range, too high, out of range too low, implausible value etc, This last byte value is sometimes described as being added to the previous five digit code, giving a resultant seven digit code. However our system translates the entire code to readable text, including the detail. In addition another byte is used to indicate the faults status, Ie Permanent [PERM], Pending [PEND], Intermittent [INT] or Historic [HIST].
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SM134 - DISCOVERY 4 (LR4) - Diagnostic Capabilities (Clear Fault Codes) |
| This function Clears all faults from the ECU memory and resets all counters. If a bus error has occurred or an ECU has been removed, it may be required to clear the fault memory of all ECU's on the vehicle. This function is also supported by the stand alone diagnostic capabilities of the Faultmate MSV-2 Extreme |
SM134 - DISCOVERY 4 (LR4) - Diagnostic Capabilities (Settings) |
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Standard Settings
The provided settings for nearly all of the Discovery 4 / LR4 / Range Rover Sport ECU's, comprise of about a dozen pieces of numerical information related to hardware and software versions, various manufacturers part numbers, the Vehicles VIN number and the Current Network status. Car Configuration File (CCF) Settings The Body Control contains a very special block of Data called a Car Configuration File (CCF). This centralized block of data actually defines and sets the current configuration settings for just about all of the on board systems in the entire vehicle. The Data block is broken down into hundreds of individually configurable settings which are then shared across the vehicles CAN network in real time so all of the vehicles on board systems can know their own configuration and that of all other ECU's on the vehicles network. By using this single source of configuration setting data, there is no requirement to have any configuration settings held in each ECU, making replacement far simpler. There is also 1 copy of this data kept as back up in the engine management ECU's should they be required and the Manufacturers IDS system also has a back up copy of the original "as Built" CCF data for every single vehicle manufactured by Ford / Land Rover etc, supplied on each DVD ROM update. For convenience, the several hundred CCF settings have been broken down into smaller sections on the same page, and absolutely all of them can be changed at will. However due to the sheer volume of configuration settings, we strongly recommend that the first step for anyone is always to save the original settings and stick with the original values for anything you do not specifically want or need to change. Experimentation is of course possible but ultimately you are responsible for any changes you make and you must consider any possible negative effect on the vehicles operationally. So we would advise against things like changing the engine or transmission type unless you really have changed the engine or transmission. Obviously it is possible to beneficially alter the way the vehicle works and functions in many cases and it is easy to add software only features / enhancements such as 4x4 info, Voice command etc. And of course the vehicle can be re configured to suit any physical additions. However in a lot of cases making changes in the CCF Configuration settings file may not have any visible or determinable effect on the vehicles functionality, this can be for a number of reasons.
Air Suspension Settings
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SM134 - DISCOVERY 4 (LR4) - Diagnostic Capabilities (Inputs) |
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time live display of the information the electronic control unit of the
selected vehicle system is currently deriving from its input sensors. ELECTRONIC AIR SUSPENSION INPUT VALUES
ELECTRONIC AIR SUSPENSION INPUT STATES
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SM134 - DISCOVERY 4 (LR4) - Diagnostic Capabilities (Outputs) |
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ELECTRONIC AIR SUSPENSION OUTPUTS CAUTION : These features will cause the vehicle to move, please ensure adequate clearance and that no body can be harmed by movement of the vehicle before using them.
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SM134 - DISCOVERY 4 (LR4) - Diagnostic Capabilities (Other) |
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ELECTRONIC AIR SUSPENSION CAUTION : These features will cause the vehicle to move, please ensure adequate clearance and that no body can be harmed by movement of the vehicle before using them.
INSTRUMENT PACK
TDV6 ENGINE MANAGEMENT
PARK BRAKE MODULE
ABS
STEERING ANGLE SENSOR
FUEL BURNING HEATER
DRIVER'S/PASSENGER'S DOOR MODULE
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