At the moment I am doing some work on the electrical system of a Hot Rod build that is mostly made up of a 2005 VZ Commodore, being built by Jim.
The good part about this project is that it is using almost all of the commodore, so the harness stays in tact and everything is guaranteed to work together in harmony.
Apart from a few small issues, the biggest headache is the ABS. The rod won't have ABS, so the instrument cluster was beeping and showing animated warnings non stop.
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| Pesky ABS Warning on the LCD Dash |
I had looked at a lot of options to fix this, the easiest was to use a BCM from a non ABS VZ ute (yes they made them) but I think nearly everyone would have optioned AC & ABS, the base option is only to get the headline price down.
In the end I decided the only way to fix it was to create a ghost system that would pretend to be the ABS. Now I could reverse engineer this, but It was going to take ages and I needed access to a working system. Convincing a friend of a friends mother that you need to plug-in an play with the family car is not as easy as you think!
This time however, I go lucky!... Even though the ABS wasn't hooked up on the rod, we still had the original ABS unit. So I hooked up a CAN bus monitor and compared the system with and without the ABS module running. This yielded three message addresses belonging to the ABS.
So now I knew that the ABS module was sending frames out on 140h, 280h, 2F0h at 21ms, 100ms and 100ms respectively. But I had no idea what the content of these frames represented. Sure I can guess, wheel speed, status, brake force, but that still doesn't help.
Suddenly I had a thought, I felt a little silly about trying it and didn't explain to those watching what I was doing in case of embarrassment..... But what do you know, it worked. I Just spammed out empty (all zeros) frames at on the addresses above at the original rates.
It seems that the BCM was happy seeing something, but nothing from the ABS module. It stopped telling the cluster to beep and flash, so now everyone is happy.
Sometimes you just get lucky.
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| Without ABS |
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| With ABS ON |
So now I knew that the ABS module was sending frames out on 140h, 280h, 2F0h at 21ms, 100ms and 100ms respectively. But I had no idea what the content of these frames represented. Sure I can guess, wheel speed, status, brake force, but that still doesn't help.
Suddenly I had a thought, I felt a little silly about trying it and didn't explain to those watching what I was doing in case of embarrassment..... But what do you know, it worked. I Just spammed out empty (all zeros) frames at on the addresses above at the original rates.
It seems that the BCM was happy seeing something, but nothing from the ABS module. It stopped telling the cluster to beep and flash, so now everyone is happy.
Sometimes you just get lucky.
