Standalone ABS?

[feef]

As part of my upgrades to the MX5, I've just found out that the stock ECU controls, among other things, the ABS. This means that I can't go over to a full standalone aftermarket ECU and will need to keep the stock ECU to control these various items. The alternator regulation, the dash and other non-engine stuff that the OE ECU does, I can work around, however the ABS has me stumped.

I've been doing some googling and see references to a BMW which has a standalone ABS module, I've also seen references to the Bosch M4 (but I'm not going to fork out £8000 for an ABS system for a 12 yr old toy), and a Teves MK60E5. There seems to be some link between the Teves and the BMW systems, but I'm not a BMW man, so am not familiar with the model designators nor if there is indeed a link.

Can anyone help identify IF there is an aftermarket ABS control system? If so, can it work with existing sensors and pumps (e.g. my new engine ECU works with many of the existing sensors and whatnot) or would it require a whole new system? Even if there IS a BMW unit which could work as a standalone system, the weight and dynamics of any BMW is going to be significantly different from a 1065kg MX5, and so could such a system be reprogrammed to accomodate?

Any thoughts?

[stevieturbo]

So you already have ABS fitted, but you want to fit another ABS ?

Dont get it ?

Other than the motorsport versions at the prices you're seeing....really doubt there is anything universal that could easily or cheaply be used....except the one already fitted to your car, which is free and already working.

[feef]

There's ABS fitted, but it's controlled by the car's main ECU.

In installing a supercharger, I'm replacing the ECU with a standalone Emerald ECU. But we've now discovered that the ABS relies on the OE Mazda ECU for operation. So, if I remove the OE ECU entirely, I need something to control the ABS in it's abscence.

[stevieturbo]

feef said:

There's ABS fitted, but it's controlled by the car's main ECU.

In installing a supercharger, I'm replacing the ECU with a standalone Emerald ECU. But we've now discovered that the ABS relies on the OE Mazda ECU for operation. So, if I remove the OE ECU entirely, I need something to control the ABS in it's abscence.

Then do not replace the OEM ecu. There is no need to remove it. Leave it in place to control all the things it needs to control, and use the Emerald to control only the things you want it to control.

[feef]

That's what we're doing for now, but it seems odd to me to leave a whole ecu plugged in to just control the ABS, as everything else will be standalone.

[stevieturbo]

feef said:

That's what we're doing for now, but it seems odd to me to leave a whole ecu plugged in to just control the ABS, as everything else will be standalone.

Didnt you say it also runs the dash too ?

That's just how things are these days, and will continue. As car makers integrate their systems, it will be harder, if not impossible to physically remove a single part without it affecting everything else.

So the easiest way to take control of what you want, is installing via piggyback. Let the OEM stuff do what it does, and you use your ecu to take control of the engine.

There may still be conflicts and errors thrown up, but it should get the job done

The other option is ripping everything out of the entire car and replacing it....rarely practical on a road car.

[feef]

easier doesn't necessarily mean it's 'correct'. I already have a solution for the dash control (well, speedo and tach) as well as alternator regulator so, ultimately, the original ECU will only be controlling the ABS. Keeping the original ECU also means I'll have to implement workarounds for other stuff, like removing the bulb for the engine warning lights on the dash as the Emerald will be controlling the engine but not the dash lights.

It is still a road car, yes, but it's also just a weekend toy and project so the "practicality" of any mods doesn't really come into it. Yes, I might be giving myself more work in the long run, but then it's done the way I want it, and not a compromise.

[feef]

...doing some more digging, it seems that from 1998 onwards, with the MK2 and MK2.5 (which I have) the ABS ECU is integral to the pump and hydraulic control unit. This makes me wonder if the link between the ABS unit and the car's main ECU is simply for error checking and dashboard alerts.

[stevieturbo]

feef said:

easier doesn't necessarily mean it's 'correct'. I already have a solution for the dash control (well, speedo and tach) as well as alternator regulator so, ultimately, the original ECU will only be controlling the ABS. Keeping the original ECU also means I'll have to implement workarounds for other stuff, like removing the bulb for the engine warning lights on the dash as the Emerald will be controlling the engine but not the dash lights.

It is still a road car, yes, but it's also just a weekend toy and project so the "practicality" of any mods doesn't really come into it. Yes, I might be giving myself more work in the long run, but then it's done the way I want it, and not a compromise.

Correct is what works, what is efficient, what is most reliable. Removing an integral part of the car that controls other stuff just because you want to fit another ecu and have it fitted on it's own...can often be a backwards step because of the knock on effects it can have in a modern car.
Again it just depends how integrated the original ecu is, and of course how able the new ecu is if it could maybe take over some of those functions.


There would be no need to remove any bulb, this can easily be triggered by your new ecu if you want. You're already at the wiring for the ecu anyway, so you have access to do what you want down there. If that's the only problem you need to overcome...you dont have much to worry about.

On some cars the car ecu can control dash, brakes, central locking, windows etc etc. So replacing those whilst retaining normal car functions...is a very difficult task.

I assume things like temp gauges, fuel gauges etc are just normal stuff, or are they also driven by the ecu ?

[feef]

stevieturbo said:

I assume things like temp gauges, fuel gauges etc are just normal stuff, or are they also driven by the ecu ?

Yup, they're all pretty straightforward.

[mrmr96]

Are you set on the Emerald? Can't you get another aftermarket ECU which will support all the functions you need?

[feef]

mrmr96 said:

Are you set on the Emerald? Can't you get another aftermarket ECU which will support all the functions you need?

The emerald was already wired in when we spotted these issues. In all the build threads I'd read I hadn't encountered this problem other than with the alternator, but it seems no one has done it with a 1.8 sport vvt engine mk2.5 like mine is and there are some differences.