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The topic of converting the S1 RX8 from DSC to Non-DSC came up recently in the Racing Forum and after doing some research I found the information and am consolidating it here in this thread It will be a work in progress, but the credit goes to Stubbs from doing an RX8-LS V-8 engine swap from this post he made in his thread as below. I'm just expanding on it further below:
Originally Posted by Stubbs
I ended up switching to a Non-DSC ABS unit since it'll work without needing the RX8 ECU.It's easier to fit too since it's about 30% smaller than a DSC ABS module. The wiring is pretty simple, it's just matching colors and adding an extra 12 gauge power wire. I also switched to a later Non-DSC ABS Master Cylinder for two reasons. First, it uses M10 fittings instead of M12, and second the fittings come out the side which gives me more room to run lines.
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So after looking over the wiring diagrams from my 2005 S1 RX8 Electrical Manual it seemed straight forward to me. At a minimum it will require the "SUMITOMO" Non-DSC ABS Module/Pump assembly and the wiring connector/pigtail which will have to be cut off from the LH engine bay harness, unless we can locate the specific connector in the aftermarket. These are different from the DSC version of same and eventually I'll post up photos of each so that the differences are documented. My hope is we can just de-pin the wires from the DSC ABS Module connector and pin them into the non-DSC Module connector, but not having gotten there yet I'm not sure if that's possible. Worst case the appropriate wires will need to be spliced instead as Stubbs did it in his post.
Essentially all the common wires between the two exist on both. So it's mostly a matter of taking those common wires from the DSC harness and connecting them to the appropriate position on the non-DSC module connector and taping off the other DSC wires not used. There may be mechanical changes needed on the hydraulic hose piping too, but again having not gotten that far yet I can't confirm those specifics yet, but that's not too difficult of a task for someone with a more advanced mechanical ability that is likely to take on this modification. That said, this is a "proceed at your own risk" process. Going to start this with the wiring diagrams for now, and add additional content over time as it progresses.
S1 NON-DSC WIRING DIAGRAM - the important thing to note is the connector diagram in the lower RH corner and the Pin designation letter positions
S1 DSC WIRING DIAGRAMS - I've marked these diagrams up to indicate which wires go to the appropriate non-DSC connector positions, and which can be discarded/unplugged/deleted
The key to making this swap is securing the connector wiring harness pigtail. I haven't been able to locate the latching connector in the aftermarket yet, but have found several more popular Mazda models that use the same one. Still searching and looking.
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The thread will be updated accordingly as time and progress permits.
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It works, just not for me since I haven’t gotten to it yet still 😅, but not too far off in the future I’m hoping. I have all the parts. RawrX8 just shared a weblink with me the other day. It appears we can now order the non-DSC wiring harness lever connector assembly rather than trying to scab one off the ever growing smaller number of wiring harnesses out there in the wild. Waiting for him to receive it and confirm.
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Just rolling through to confirm a working Sumitomo ABS swap into my originally-DSC car using this wiring write-up.
My use-case is a 2005 car (bottom port master cylinder) with a Keisler LFX swap. Before I realized that rx8 brake masters had different fittings between non-DSC/DSC I had ordered a brand new oem replacement master cylinder (base model, bottom port) so I was committed to using that. The brake plumbing turned out to be the most complicated part for this ABS swap. I ended up finding a part-out and getting some oem hardlines from the master to the ABS pump. One thing I found is that the DSC brake hardlines use a bubble flare, whereas the non-DSC use an inverted flare, so I bought adapters from eBay. The rear brake lines go into a different spot on the ABS pump, so I had a friend just make me some short hardlines and I used a union to adapt them.
As far as the wiring, I followed the write-up in this thread (and had a cut pigtail with the ABS pump), and I used Deutsch connectors so it would be easy to re-pin if I screwed it up. The only thing that threw me was the power wiring where it says to remove a fuse. I ended up leaving the fuse and actually just putting both ABS power wires to the one from the fuse block. I didn't mess with it much after getting it working. Otherwise, pretty straightforward. Also I directly spliced the powers and grounds rather than buying specific big-gauge DT connectors.
The only real issue I'm having is that if I hook my ABS scanner to the car the whole system will throw an ABS code (c1214). I went and tested on the street (after clearing codes) and the ABS worked fine, and I completed my first track day yesterday without any hiccups and functioning ABS all day (120 track miles and 400 miles of commute to the track and back). I also tested by plugging in my spare ABS pump and I get the same code. Not sure why and I'm not going to probe it too much further since it appears to be working just fine.
Just rolling through to confirm a working Sumitomo ABS swap into my originally-DSC car using this wiring write-up.
My use-case is a 2005 car (bottom port master cylinder) with a Keisler LFX swap. Before I realized that rx8 brake masters had different fittings between non-DSC/DSC I had ordered a brand new oem replacement master cylinder (base model, bottom port) so I was committed to using that. The brake plumbing turned out to be the most complicated part for this ABS swap. I ended up finding a part-out and getting some oem hardlines from the master to the ABS pump. One thing I found is that the DSC brake hardlines use a bubble flare, whereas the non-DSC use an inverted flare, so I bought adapters from eBay. The rear brake lines go into a different spot on the ABS pump, so I had a friend just make me some short hardlines and I used a union to adapt them.
As far as the wiring, I followed the write-up in this thread (and had a cut pigtail with the ABS pump), and I used Deutsch connectors so it would be easy to re-pin if I screwed it up. The only thing that threw me was the power wiring where it says to remove a fuse. I ended up leaving the fuse and actually just putting both ABS power wires to the one from the fuse block. I didn't mess with it much after getting it working. Otherwise, pretty straightforward. Also I directly spliced the powers and grounds rather than buying specific big-gauge DT connectors.
The only real issue I'm having is that if I hook my ABS scanner to the car the whole system will throw an ABS code (c1214). I went and tested on the street (after clearing codes) and the ABS worked fine, and I completed my first track day yesterday without any hiccups and functioning ABS all day (120 track miles and 400 miles of commute to the track and back). I also tested by plugging in my spare ABS pump and I get the same code. Not sure why and I'm not going to probe it too much further since it appears to be working just fine.
So I have also converted my 04 from DSC to non DSC and im getting the same code as you. I however do not have working ABS. Flat spotted my brand new tires at two events now and desperate to get this working. I have two sumitomo abs modules and having the same issue with either. I thought my module was bad since it was throwing that code but yours is working with the code? If I erase it it comes right back when I hard brake it seems. After erasing the code repeatedly and rescanning sometimes I get a similiar code for a different valve and sometime no code. I am able to see wheel speed signal on all 4 sensors and the dash is getting speed. Driving me nuts this isnt working
09-26-2021, 05:13 AM
DIY: Converting the S1 RX8 from DSC to Non-DSC
