Arduino BCM Emulator

They go by many names, P01, P59, VPW, '0411 etc. Also covering E38 and newer here.
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evilstuie
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cars: 1985 Pontiac TransAM

Arduino BCM Emulator

Post by evilstuie »

Hi All,
Does anyone have any designs or code to create an Arduino Module to monitor the BCM for module checks such as SRS or ABS and send back the required "OK" message?

This is basically to eliminate the annoying chime messages on the VY/VZ dash clusters when the module is faulty, or more specifically missing when doing a custom swap.
My 85 TransAM has a VY dash installed along with the BCM, most of the commodore wiring and an LS1 swap as well.

Having no ABS module, Traction control, SRS, airbags or other modules,t he ABS, and Traction control messages are very annoying for startup, as well as interrupting engineering mode, and will also pop back up at random times while driving.

As the BCM is the master and sends out requests for the modules to respond to, I assume it would be relatively easy to have an Arduino module with looped code listening for specific packets and responding with the appropriate message to eliminate these, seeing as neither the cluster or BCM can be easily reprogrammed or modified to do this.

I've seen that different BCM models and years may have slightly different request and response packets, depending on the SRS setup and such so any data that would be useful to put a project together would be appreciated.

I have just started with Arduino so it'll take me a bit to get up to speed, but so far it seems very simplistic and straight forward so I'm sure it can be done without much effort.
pman92
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Re: Arduino BCM Emulator

Post by pman92 »

Hey mate,

See the link below, I sell a module that will do exactly this.

If you want to do it yourself with an Arduino and have any questions let me know. There's all the information you need already on these forums if you dig deep enough.

Cheers
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MrModule.com.au
evilstuie
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Re: Arduino BCM Emulator

Post by evilstuie »

pman92 wrote:Hey mate,

See the link below, I sell a module that will do exactly this.

If you want to do it yourself with an Arduino and have any questions let me know. There's all the information you need already on these forums if you dig deep enough.

Cheers
Yeah I had a look around and found some of the code for capturing the data, but not enough to know what I'm looking for and what to send back.
I'd like to have a go at it myself if I can. Are you able to post or message the code and I can have a go myself?
Does it need any additional modules or will the UNO R3 have everything needed?

I already have the BCM installed and wired into everything in the car, but I'm not sure to what extend I actually need it. I don't use any of the OEM security (VATS etc), and my windows locks etc run direct, the BCM just gets the notifications or what not when they're activated, possibly the only things that might be an issue is headlights, indicators and wipers, as I think they all run through the BCM.

Maybe just a module that sends the ABS and SRS messages as an addon is the easier option than reinventing the wheel and rewiring the whole car (again).
pman92
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Re: Arduino BCM Emulator

Post by pman92 »

Since ALDL is single wire you will need a way to convert the TX and RX pins into a single wire. There's a couple of example circuits in my for sale post and if you search old topics you will find them as well. Your code needs to account for or work with the "echo" that you will probably receive (depending on circuit) every time you transmit something.

Here's a couple of topics that might be useful

viewtopic.php?f=10&t=6811

viewtopic.php?f=10&t=724

VT/VX data is different to VY/VZ (but very similar). You will find data logs for both on the forums if you dig deep enough.
Once you have the data format you can experiment changing the contents of the data as well.

Transmitting is no harder than receiving. You can use the checksum calculation in the receive code you found to work out how to calculate it to send data as well.
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evilstuie
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Re: Arduino BCM Emulator

Post by evilstuie »

Ok cool, thanks for that.

One last question, what (if any) role does the PIM play in the system?

I was just thinking and I think the original PIM I had in the car was a VX ute PIM, which its possible it didn't have Traction control.
It was only AFTER I put my 2nd body harness into the car that the ABS fault messages started coming through so I'm just wondering if the PIM is intercepting anything and sending data to the cluster?
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Re: Arduino BCM Emulator

Post by antus »

the pim translates between vpw or can and aldl, so newer standards of pcm can work in an older mostly aldl network in the car. it only translates a handful of things it knows about, mainly for the dash, but would also include abs for traction control handled by the pcm and the abs together.
Have you read the FAQ? For lots of information and links to significant threads see here: http://pcmhacking.net/forums/viewtopic.php?f=7&t=1396
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