MoTeC Global Forum

Hi,

I am trying to retrieve the 4 wheel speeds off the CAN bus in a Porsche 996 so we can use them for traction control in m1/LS7 combination .

I had a go with the CAN inspector software but CAN really is above my head at this stage. Can anybody assist me with this or would it be easier to send support an email?

If so what data files do you want? Have attached a the can inspector file, and also the config file out of the ADL2 that was in the car. I am currently converting it to use a C187 instead.

Thanks for your help...

You are likely going to be best to contact one of the developers on the forum, or a dealer that has experience in this area.
Its generally not something that is going to be done free of charge for you.

CAN reverse engineering is a lot trickier than just sending someone a log and getting the addresses/scaling in return.

Does the 996 you gathered the data with have a Motec Dash? If so and you want to do this yourself, you could create a config to receive/log the various CANid shown in the CAN Inspector output. Start by creating a channel for each byte of the messages. Now drive the car, and look at the data to see if you can figure out which channel looks like wheel speed. Or put it on a lift and arrange to spin just one wheel and using monitor channels figure out what changes when you do that.

rntechnologies wrote:CAN reverse engineering is a lot trickier than just sending someone a log and getting the addresses/scaling in return.

So much truth there! Richard at MSEL in Auckland can do it if you want to go that way. I see in the dash config you have one speed input configured on SPD 1. Is this an extra sensor reading the Porsche chopper wheel?

My personal choice would be wire wheel speed sensors to the M1 direct. Either use the Porsche ones or something aftermarket. The car I normally work on sends wheel speeds via can bus and works fine, however if you go direct it's one less thing that can fail. Also, if you do do it yourself, there's a lot of thought to go into the can addressing. Different addresses have different priorities etc, plus depending upon what else you're trying to do you may need to run 2 or 3 can buses.

rntechnologies wrote:You are likely going to be best to contact one of the developers on the forum, or a dealer that has experience in this area.
Its generally not something that is going to be done free of charge for you.

Adrian from support had a look at it for me and didn't find any wheel speeds on the CAN.

Sean, as far as I know that is a factory sensor that has had its signal spliced, one to the ABS and one to the Dash. I am yet to find exactly where it has been spliced. I have managed to get a wiring pinout for the 996, and have traced two wheel speeds outputs from the ABS to an unused plug that sits on the tunnel beside the driver. So I am coming up with a plan to go from the plug to the dash to see if they are actual speed outputs. Unfortunately the wiring pinout I have is in German so is hard to follow what some of it does. Bosch is looking into it for me too.
Ideally I'd wire them straight to the M1, but I don't want to try splice the sensors and then muck up the factory ABS. Replacing them is an option, Im just trying to work with what I have currently before I start getting new parts etc.

I’ve bought all my Porsche CAN templates form Chris brown. He has mapped most of the cars in detail.

http://www.cb-racing.com