CAN (Controller Area Network)

[Cosmo Dude]

Anyone played with this?
It's the data networking that the various parts some/modern cars use to communicate.
http://en.wikipedia.org/wiki/Controller_Area_Network

[zappy65]

Yes I "play" with CAN BUS Systems all the time, what do you want to know?

[maztech]

Yeh heaps of times get the most/all CAN faults i get at work, what did you want to know

[Cosmo Dude]

Mmm, OK.
Do you have the schematic of what is on the standard Mazda CAN bus? Think Mazda 3.
Does the Mazda bus use standard 100 ohm terminating resistors?
I have a Mazda 3 ABS (not traction control) does it require inputs from the bus to operate correctly? I.E. guage cluster

[maztech]

Dont know bout resistors, you do need each module for all to work properly, all the clubman cars to run standard PCM need each module to communicate to make it run right.If you want to run a 3 motor in something get a NEO manual as these cars are the easiest to use as there are less modules. I looked into building a clubman and still want to do it but i dont have the 30 grand for one.

Cosmo have a look at Oz Clubies Forum to see what these guys get up 2

You need to include cluster ,pcm, power steer and ABS ( but get a car without ABS to make things easy)

Another thing is you have to include the imob system as well to make it all run.

[Cosmo Dude]

I'll have a look at Oz Clubies. Thanks
It appears to me that the cluster is the home of all remote devices while ECU will talk to PCM and Traction Control Unit.
I may be able to use the ABS with a dummy dash cluster and maybe later add in a MoTeC M400

[maztech]

Yes the cluster is a major part of the network and it is my understanding that you have to use it as it is a hub for CAN and the imob system. My plans wre to get it regoed then take it all out and fit aftermarket system , think it is the easyest way to go so you are not running surpluss equipment. Certainly if you want the abs to work you maybe able to link some parts together. What are you doing with all this , are you planning a motor transpant?

[Cosmo Dude]

Stage one is to get the ABS working after that I may look at using a MoTeC M400 to control a BP turbo (for track use only as I'm in Victoria, the no fun state).

[maztech]

Why dont you just use the system out of a v6 as you dont need any CAN parts ,then you should be able to just get a brake mod compliance as the ABS is out of another ba.
Put turbo on get that plated then put motec on and say nothing to them.

[Cosmo Dude]

BA ABS is BANG, BANG, BANG.
The Demio (same as 3) ABS is Brrrrrrrrrr.
Anything i do will need an engineers cert so why not go for the best.

[zappy65]

Originally Posted by Cosmo Dude

Mmm, OK.
Do you have the schematic of what is on the standard Mazda CAN bus? Think Mazda 3.
Does the Mazda bus use standard 100 ohm terminating resistors?
I have a Mazda 3 ABS (not traction control) does it require inputs from the bus to operate correctly? I.E. guage cluster

Yes, the ABS unit does use standard 100Ohm resistors
Yes, the ABS does need inputs from the BUS via the PCM

Originally Posted by Cosmo Dude

I'll have a look at Oz Clubies. Thanks
It appears to me that the cluster is the home of all remote devices while ECU will talk to PCM and Traction Control Unit.
I may be able to use the ABS with a dummy dash cluster and maybe later add in a MoTeC M400

You will not be able to run a "dummy cluster" because the cluster has the immobilizer built in to the back of it and this needs to be programmed to the PCM which needs to be programmed to the ABS etc etc...

There is no ECU as such in a Mazda 3, all to do with the PCM, if you want the ABS to work with a dummy unit, you will need to get the immobilizer coded to the PCM

The cluster is the central point of the CAN BUS on a Mazda 3, without the cluster, nothing operates (mainly because of the immobilser unit)

So you will need a blank ABS module, a blank cluster and it will need to be programmed to each other (2nd hand units can NOT be reprogrammed)

No idea how an A/M ECU will work in those things...because the ABS module takes outputs from the speed sensors, gives them to the PCM and the PCM sends the info through the CAN BUS through the cluster, back through the PCM and back through to the module.

The Immobilizer needs to be programmed to the PCM and visa versa

The Traction control communicates with the ABS module and the PCM, they are all interconnected via the CAN BUS

[Cosmo Dude]

I'm missing something here...
PCM in BA talk is Power-train Control Module and controls the auto trans where equipped.
What is PCM in your speak?

[maztech]

PCM same same - use a BA unit as there are alot of things that make the CAN system ABS /traction control systems work.

[zappy65]

Originally Posted by Cosmo Dude

I'm missing something here...
PCM in BA talk is Power-train Control Module and controls the auto trans where equipped.
What is PCM in your speak?

That is correct PCM = Power Train Control Module
And TCM, which the Mazda 3's dont have refer to the transmission control module. Things like the CX7 and CX9 have those...

I am kinda confused about what you wished to achieve Cosmo?..what exactly do you want to do...

I definitely know a BA PCM wont work in a Mazda 3?...if thats what you wish to achieve, but I think not...lol

EDIT: I think you may wan to put a Mazda 3 ABS system into a BA with a BPT?...Correct?..If thats what you want to do, it wont be easy bud as the ABS module (which will have to be new) wont recognize the Motec, and it wont work...

[70NYD]

doesnt abs on the ba work with a grouved hubring and a sensor that senses when this hub ring is not moving under breaking therefore releasing the breaks a little???
if so, wouldnt it be easier to get a new ring machined up, with a lot more smaller grouves which will make it go brrrrr

[maztech]

Yes they do work on a ring system and by changing the ring it would mess with the system as they are programed to the number on the ring causing it to not function properly

[70NYD]

i meant if you double the number of grouves it should double the response time, cus it would trick the system, it wouldnt function "properly" by the mazda book, but it might give what cosmo is after

[Cosmo Dude]

Number of teath on the ABS tone ring isn't realy relevant unless you're trying to calibrate a speedo. ABS doesn't care if you're going 40km/h or 400km/h it's about the ratio between the wheel speeds and/or rapid change in those speeds. I could have opted for the full traction control system but i knew that needed too much intra system interaction.

[maztech]

Goodluck getting it all to work

[Aaron]

Cosmo, are you sure the controller is responsible for the actual pulse rate? I would have put the "blame" on the hydraulic side of the system, and if it gets a pulsed driver input what about just using a frequency multiplier on that side of the system.

As for CANBUS it's pretty cool, I've done a lot of work with this in Clubmans now and to clear up some facts...

* No termination resistors are needed on the Mazda3/Ford Focus

* To use PATS you must have the Cluster, Key and ECU combo that are coded together, but you can turn off PATS and/or recode yourself with the right gear/software

* The ECU is a dumb device and doesn't "miss" the ABS or other vehicle systems, it talks on the CAN-HIGH bus while the cabin fuse box talks on both CAN-HIGH and CAN-Mid and will tell the ECU there's a problem if you don't have one of the modules that it thinks you should have in place. The same software that can do the PATS stuff will let you change the expected feature set of that unit.

* There is another approach a guy in Melb has developed and he simply clones the handshake data on the CANBUS that it broadcast during a key-on-key-start process so you don't need to bury an instrument cluster pcb somewhere.

* In a Mazda3 it's failry typical fo the the ABS module to also provide the roadspeed data onto the CANBUS, this is no drama unless you change the tone rings etc then it'll throw up errors. One approach for locost builders is to mount a single tone (appropriately toothed) ring on the tailshaft coupled to all 4 inputs of the ABS module so that the module is sure there's nice even rotations. That does develop a error code for a mechanical failure in the braking system, but that doesn't hamper power generation. A Focus on the other hand uses a convention in-gearbox speed sensor and develops no-codes

Just some thoughts...

You'll find good info on Oz-Clubbies in "the duratec thread"... It's a long one and has most of my research notes there, plus a bunch of work by others pulling stuff apart they didn't have to

A.