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What is the CANBUS?
07-19-2009, 02:00 AM,
What is the CANBUS?
sorry everyone im completely new to this type of stuff, what is the CANBUS system?
07-19-2009, 10:50 AM,
RE: What is the CANBUS?
(07-19-2009, 02:00 AM)rbailey83 Wrote: sorry everyone im completely new to this type of stuff, what is the CANBUS system?

The CAN Bus is an automotive bus developed by Robert Bosch, which has quickly gained acceptance into the automotive and aerospace industries. CAN is a serial bus protocol to connect individual systems and sensors as an alternative to conventional multi-wire looms. It allows automotive components to communicate on a single or dual-wire networked data bus up to 1Mbps.

Before CAN Bus
Since the early 1940's, automakers have continually improved their vehicles' technology by integrating an increasing amount of electronic components. As technology progressed, the vehicles became more complex as electronic components replaced mechanical systems and provided additional comforts, convenience, and safety features. Up until the release of CAN Bus, vehicles contained enormous amounts of wiring which was necessary to interconnect all of the various electronic components.

[Image: diag_canbus1.jpg]
Due to the vast amount of wiring, an after market installation requires the installer not only to understand how the integrated systems communicate with each other, but also requires numerous connections to be made throughout the vehicle. To make matters worse, the vehicle wiring differs between vehicle years, makes, and even models. As a result, installers need to be highly knowledgeable and perform intensive labor for the most trivial after market equipment or the installation shop experiences countless hours of lost time on troubleshooting and sometimes even expensive claims for damaged OEM equipment. During this progression, installation shops have had an increasingly difficult time finding qualified staff that are able to perform everyday installations and as a result, have either had to increase their prices to compensate for the required specialization and labor, or simply had to turn away the customers who owned complex vehicles.

[Image: diag_canbus3.jpg]
Introducing CAN Bus
The BMW 850 coupe was the first CAN Bus vehicle to enter the market in 1986. By reducing the vehicles wiring by 2km, the vehicles overall weight was significantly reduced by at least 50kg and using only half the connectors. For the first time, each of the vehicles systems and sensors were able to communicate at very high speeds (25kbps - 1Mbps) on a single or dual-wire communication line as opposed to the previous multi-wire looms. However, the introduction of CAN Bus also increased the vehicles complexity and made after market installations even more difficult and in many cases impossible to perform.

[Image: diag_canbus2.jpg]
In 2006, over 70% of all automobiles sold in North America will utilize CAN Bus technology. Beginning in 2008, the Society of Automotive Engineers (SAE) requires 100% of the vehicles sold in the USA to use the CAN Bus communication protocol while the European Union has similar laws. Several new after market devices have been introduced into the market that utilize the CAN Bus protocol but until now, there have been no new devices that assist the aging after market remote starter and alarm system technology. Now there is an after market module that offers remote starter and alarm connectivity to the CAN Bus communication protocol.

[Image: diag_canbus4.jpg]
The CAN SL is the first after market CAN Bus bypass kit to offer connectivity of aging remote starters and alarms to the new high speed CAN Bus communication protocol.

Further explanations:
CAN Bus is a multiplexed wiring system used to connect intelligent devices such as Electronic Control Units (ECU's) on vehicles, allowing data to be transferred in a low-cost and reliable manner. CAN means 'Controller Area Network' and was developed by Bosch in 1980. Most new vehicles use this system and it is becoming increasingly difficult to install after-market products without using a CAN Bus Interface.

Why is this system used?

The reasons for the vehicle manufacturers using CAN Bus are:-

(a) Significant reduction in wiring leading to:-

(i) Significant reduction in manufacturing cost and hence retail cost.

(ii) Reduction in weight resulting in improved fuel consumption.

(b) Reduced number of interconnections hence improving reliability.

How can I find the CAN Bus Wires?

It is easy to identify the wiring as it is just a twisted pair of thin wires. These will be found all over the vehicle - sometimes in with a conventional main loom. The wires are called 'CAN High' and 'CAN Low' and it is important that any interface is connected correctly to these wires. All Bridgwater Electronics Interfaces have an LED to indicate when the wires have been connected correctly.

What aftermarket products will require a CAN Bus Interface?

Most of the higher specification GPS Navigation systems will require a speed pulse signal as a minimum. Many also have inputs for illumination and reverse signals. On CAN Bus vehicles these signals may not be present so a CAN Bus Interface will be required.

How does this relate to Motorcycles?

The Canbus system in its fullest implementation could allow for a single communication line and a single power supply to be shared among all components. For example a turn signal could be a module, supplied with power and the data communication would tell it to turn on and off. Additionally all of these modules would not need to be fused as they would monitor current and if a short or other fault occurs, would disable the circuit until the fault was cleared. There could be a module for the headlights, horn, brake lights, etc.

The implementation on our motorcycles is the same except that all control “modules” are contained in a single chassis control module called the ZFE. This ZFE has inputs from all switches and controls and outputs to all components. Each brake light switch has its own input as does each switch on the handlebar controls. Sidestand switch, clutch switch, neutral, etc are also input to the ZFE as individual inputs. Each powered component such as horn, lights, windshield, etc. has its own output from the ZFE. The ZFE has the software logic to determine what output occurs based upon one or several inputs. Each output is fault protected and most are fault tolerant as well, meaning that as soon as a fault is corrected an output will resume its normal function without the need for external intervention.

We do not need to be afraid of attaching external devices to the Canbus equipped bike, we just need to be careful not to overload any of the ZFEs protected outputs. Any of the outputs can also drive a relay without fear of triggering a ZFE fault. Some of the ZFE outputs such as the one for the taillight, monitor for over as well as undercurrent situations. An undercurrent situation (burned out bulb) in the taillight will cause the ZFE to run the brake light at reduced brightness for safety until the defective bulb is replaced. Under that situation you will see a fault indicated on the instrument panel. As soon as the bulb is replaced the fault will clear and normal function will resume. Any additional lighting for brake lights or taillights should be implemented using relays and most importantly the original bulbs must be left in place or a fault could be triggered. LED taillight replacements must be designed to account for the ZFE monitoring, by employing circuitry that draws enough current to let the ZFE “know” that the bulbs are functioning.

For external equipment I would recommend one of two different approaches. For small equipment such as a GPS, radar detector, communication system or satellite radio, there is an auxiliary equipment connector just in front of the battery. It is a three-pin connector consisting of a ground (brown wire), power supply (red with white trace) and speed pulse (blue with green trace).

For auxiliary lighting I would recommend a relay driven from the low beam headlight wiring. Using the running light circuit to drive this relay takes it out of the “load shed” group and will allow your auxiliary lighting to remain on while starting the engine. Using the low beam headlight wiring (yellow with white trace) has the advantage of remaining off until the engine is started to prevent unnecessary load on the battery during the high load event when starting the engine. An additional feature is that this allows you to turn your key on to enable the GPS, radio or other accessory without the headlight or auxiliary lighting being on and draining the battery. On the K1200S the wiring to the headlight is easily accessible in behind the cover just to the right of the instruments. On the GT the wiring is in the same place, but lacks the exposed wiring that is on the S. I had to cut through a layer of cloth tape in a harness to expose the yellow/white wire to control the relay for my MotoLights. The actual plug and wiring for the headlights is behind the instrument cluster. There is no reason to fear using this headlight wiring to control a relay, by nature the headlight control line must be robust enough to control between 5 and 10 amps of lighting allowing for one or two 55-watt bulbs.
DelonixRadar - your no BS, unbiased resource on radar detector, and speed camera products.
08-19-2009, 11:10 PM, (This post was last modified: 08-19-2009, 11:11 PM by iamfriendly.)
RE: What is the CANBUS?
Here's some more info on CANBUS:-

Morten Moller of Sensor-Technik UK explains the background to CANbus control, from where it's used to how it operates.

CANbus control units and HMIs (human machine interfaces) are used in a wide variety of functions in mobile and stationary applications.

Via the various configurable inputs and outputs it is possible to connect all types of sensors and actuators directly to the control unit; the user-programmed controller monitors the system inputs and allows either closed loop or open loop control of the outputs.

This way, components such as proportional valves can be controlled directly.

Together with extended diagnostics functions and the CAN interface, the system offers unmatched in-service facilities.

In case of failure (such as broken cables or short circuits) it allows users to restore the vehicle to safe conditions and provides service staff with the right tools for quick and easy diagnostics.

With the additional possibility of remote (wireless) maintained diagnostics, the CANbus is capable of making a significant contribution to increased vehicle availability and productivity.

More and more vehicle manufacturers and automotive component suppliers are realising the benefits of the CANbus system.

This technology has now reached a stage where internationally agreed standards exist, so that different manufacturers' electronics can communicate together.

A typical modern truck might have separate electronic modules controlling engine, automatic gearbox, ABS brakes and onboard hydraulic control.

The engine module has a sensor reading rotational speed.

All the other modules, such as the gearbox, need to know the engine speed to operate correctly.

The engine module will broadcast the engine speed message on the CANbus, and a module connected to the bus can receive the message and use that information.

This means that the engine speed sensor need only be connected to one of the modules.

The versatility of CANbus modules is evident from the wide range of applications in which they are used.

They include specialised civil engineering, mobile cranes, agricultural/harvesting machinery, forklift trucks, refuse collection vehicles, steamrollers, aircraft towing vehicles, road sweepers, excavators, fire engines, military equipment, boats, shipyard cranes and diggers.

But what's the background to this technology?.

The Controller Area Network (CAN) was originally developed by Bosch for use in the automotive industry, but has established itself as the standard bus system for mobile applications, and is defined under ISO11898.

CANbus systems exhibit high transfer rates up to 1Mbit/s and high data transmission reliability.

A number of different capabilities (CRC, frame checking, acknowledgement, bit monitoring and bit stuffing) enable the CAN protocol to recognise errors in the transmitted data (caused for example by electromagnetic disturbances) and to correct them.

This correction takes place with very little loss of time, making CANbus extremely reliable in demanding applications.

A pair of wires forms the transmission medium.

The length of the network can be up to 40m for the maximum 1Mbit/s transmission speed, but networks can be up to 1000m in length without the need for repeaters and are practical for transmission rates of 80Kbit/s or less.

The number of nodes on the network is unlimited in theory, but in practice depends on the type of chip used.

With commonly used chips, 32, 64 or up to 110 nodes per network are possible (or 128 with restrictions), whilst further nodes can be accommodated by using repeaters or bridges.

CAN is a "multimaster system" with line topology and real-time capability.

Unique "identifiers" contain information not directly related to the address of a participant, but to the contents of a message (such as temperature, rotational speed or linear speed).

All participants check out the identifier being transmitted and decide if the type of message is relevant to themselves.

In this way, all messages can be received from many or all of the participants simultaneously.

The unique identifier also determines the priority of the message relating to bus access.

Should a number of participants try to access the bus simultaneously, the higher priority message is guaranteed to gain bus access.

Standard format (11bit identifier) and extended format (29bit identifier) are two different message formats that can exist on the same physical CANbus.

The CAN 2.0 B specification supports both formats, whereas CAN 2.0 A only allows frames with 11bit identifiers.

Through content-oriented identifiers in the message, the system achieves a high degree of configuration flexibility and allows a simple extension of the network to include further devices.

09-08-2009, 10:09 AM,
RE: What is the CANBUS?
OK, you've just confused the heck out of me! LOL I think I'll just get my son to install the next accessories I need installed. He's a whiz kid with all of the electronic systems in a car. I can do the plain old mechanic work but the electronics just slay me!
09-08-2009, 10:11 AM,
RE: What is the CANBUS?
Here is a list of CANBUS vehicles:

In the USA, ALL vehicles from 2008 onwards will be CANBUS
In Australia, MOST vehicles from 2008 are CANBUS

Prior to 2008, the following models are CANBUS:

Audi 2002 onwards
BMW 2002 onwards
BMW 3, 5, 7 Series 1998 onwards
Ford Fiesta 2006 onwards
Ford Focus 2005 onwards
Ford (other) 2008 onwards
Holden Astra 2004 onwards
Holden Vectra 2002 onwards
Holden (other) 2008 onwards
Jaguar 2002 onwards and also ALL S types
Mercedes 2002 onwards
Porsche - Cayanne, Cayman, Boxster
Skoda 2005 onwards
Saab 93 2002 onwards
Saab 95 2002 onwards
Seat 2005 onwards
Vauxhall Astra V
Vauxhall Vectra C
VW 2005 onwards (incl Golf Mk5, new Passat, new Polo)
Volvo 2003 onwards
DelonixRadar - your no BS, unbiased resource on radar detector, and speed camera products.
09-09-2009, 10:47 AM,
RE: What is the CANBUS?
Thanks administrator! That explains it much better to me. I have a Chevy club cab pick up that I've got my radar detector on. My son is 16 and he actually did put in the radar detector for me a couple of years ago. He's a whiz kid and I think has a great future as an installer for electronics. Heck, he makes as much as I do just on the side!
10-29-2009, 09:25 PM,
RE: What is the CANBUS?
Hey Rbailey.
Myself Millermccullum and I read your entire posting. Welcome to the forum Rbailey. In my view....,

CAN Bus is a multiplexed wiring system used to connect intelligent devices such as Electronic Control Units (ECU's) onto vehicles, allowing data to be transferred in a low-cost and reliable manner.

CAN means 'Controller Area Network' and was developed by Bosch in 1980. Most new vehicles use this system and it is becoming increasingly difficult to install after-market products without using a CAN Bus Interface.

At Bridgwater Electronics we develop and supply a range of CAN bus interfaces for automobile after-market service providers.

Anyways Thanks. Stay Connected
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