So I have an adaptronic e420c which I've had modified by the adaptronic importer over here to have the necessary 2 extra inputs so I can have a sensor peer wheel. I also have a guy who can put together the reluctor converter circuits to change the wave form from a analogue to digital type that the ECU needs.

The circuit has been tested working on a 5 that does not have abs fitted.

As my car has abs fitted I was thinking about tapping into the abs lines to use the stock abs sensors and trigger wheels to provide the signal to the ECU.

What we are not sure of is if going down this route, will the abs continue to function or throw up error codes/dash lights and wool the tc work?

Can anyone confirm if this method will work or not?

If it will work are there any other adaptations I need to make to the setup?

 

only one way to find out
in for results

 

I dont see how it will be an issue depending on the input circuit, especially if opto...

 

Yes, with a but:

You're describing "a guy who can build a circuit." Provided that "the guy" builds "the circuit" in such a way that it has a high input impedance (eg: 10s of kΩ) and does not apply any sort of pullup voltage to the sensor, then yes, it will work just fine.

These criteria (high impedance, no pullup) are usually assumed to be true of any input circuit designed to receive a signal from a VR-type sensor (eg: ones based on the MAX9926 IC), however speaking as an electrical engineer, I can assure you that you can always find a way to **** up even the simplest circuit design if you try hard enough.

I predict a 95% chance of success, presupposing that "the guy" is a competent engineer.

(I'm assuming that the Miata does, in fact, use VR sensors on the ABS. I have utterly no idea if this is true- I've never owned one that had ABS.)



I doooooont know.




Yes. You can.

 

Does the Adaptronic have the ability to cut injector pulses, or is it just going to retard the timing and blow the motor up?

 

Thanks for the replys so far.

Yeah I'm tempted to just do it, however I've done that before with unintended results.

I should have quantified who the 'guy' was really, sorry. He's certainly an auto electrician as a minimum but has some other strings to his bow I think. I became aware of the board he put together on this thread. Pics of the board about half way down. I'll chat to him about the points you make, electrical stuff ain't my forte tbh.

Malcolm's Race Car Build - Page 56 - Members Rides - MX5Nutz Forum - Page 56

Yes it can cut fuel and/or ignition.

 

Looks like a very simple circuit, with a diode to rectify the voltage and a transistor to make it a square wave. No zero-crossing detection.

 

From a little reading zero crossing detection would be beneficial? Will I encounter problems without it?

From looking at the Mazda workshop manual for this year a sine wave is what to look for with an oscilloscope to check the abs is running correctly so I guess it must be a reluctor type.

 

..... or they could be current loop hall effect?

 

IIRC the cable from each sensor is a shielded twisted pair, which suggests (to me) VR. If it were me, I'd just use a MAX9926, which is properly differential, and be done with it. I can't imagine why anyone would try to build a fussy, discreet, SINGLE ENDED circuit.

EDIT: I wrote that without following the link. The circuit on the board is not single end as I'd assumed. It'll be interesting to see how the OEM abs computer feels about it.

 

Without a schematic, it's impossible to know for certain.

So long as he's not grounding out one side of the signal, it'll probably work just fine.

 

Joe speaks truth.

 

OK, thanks for all the advice. I'm going to give them a go. At about $30-35 dollars for 4 circuits they are worth a punt. I'll post up here with results when I have them. That may be a while though as I think I've damaged my clutch thrust bearing on track over the weekend.

 

wait? how is 4 diodes and 4 transistors $30-40????

 

Labor.

Some of us value our time.

 

Just thought I'd add that the circuits got installed today and so far they are working perfectly! Thanks for all your advice and comments.