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Discussion Starter · #1 · (Edited)
i didnt find a ABS related forum, so i post that here - feel free to move to the right place.


ESP8266 based, KiCad + Source will be provided.
You can use a mobile phone or a laptop to connect to the WIFI AP and then there is a little webapp to control the EBC.

Should work for all Lotus with EBC430 ABS. Developed on a MY10 1ZZ Elise S

If anybody has the details of what the Lotus Scan Tool does in terms of which "procedure" it actuates the valves id like to know ;)

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GITHUB Project -> cloudn1ne/LotusABS
 

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Hopefully won't be using the OE ABS for much longer! I found that if I did a few ABS stops after the initial bleed, I could get any trapped air out of the ABS valve block.

I think you would just need to pulse all of the valves in order to move air bubbles through the system and back to the reservoir or out the calipers.
 

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Hopefully won't be using the OE ABS for much longer! I found that if I did a few ABS stops after the initial bleed, I could get any trapped air out of the ABS valve block.

I think you would just need to pulse all of the valves in order to move air bubbles through the system and back to the reservoir or out the calipers.
I recently installed SS Brake Lines and am currently trying to bleed the ABS system. I got the initial bleed completed using an EEZI Bleed with no air observed. Brake pedal is very soft and requires double pumping to get pressure. I'm going to try to induce the ABS system under hard braking, in a controlled area, and re-bleed. If I can't get that to work, the nearest dealer is a 3hr drive each way... Would be great to have something like the OP!
 

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Hey what's brings you back here?

I've buy 2 weeks ago a VAG-COM cable with a switch on it, with the intention to communicate with the ABS430... Like this one:



But you're were faster. And I am happy that you have done it. I've just had a look at your code and it seems very clean, congratulations.

Maybe I will port your application for PC with that cable. For now I've "just" successfully flash a T4e, with this cable;)

If you're add this cable to your wishlist, I'will be glad to offer it to you:)
 

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Discussion Starter · #8 ·
The need to bleed my brakes and being lazy mostly. I have started to reassemble my Lotus that was laying around in pieces for the last 2 yrs.
Thats a cool cable - you can probably just take the logic (raw bytes) from my prog and recycle that code. I only had a default Pin 7 KKL cable, so i went with a custom PCB.

Next challenge is the Airbag controller ;-) Then im through with everything that has a microcontroller in that car.
 

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Discussion Starter · #9 ·
Maybe I will port your application for PC with that cable. For now I've "just" successfully flash a T4e, with this cable;)

If you're add this cable to your wishlist, I'will be glad to offer it to you:)
thx for the offer, but i need the CAN part for my T4e's - i will probably end up doing a PCB that can do CAN and K-Line (so far i have em separated) - it is just hard to find a proper OBD2 cable that has all pins on the DB9m and i didnt really look hard for a pcb edge solder connector - making a dongle + 3d printed case would be sweet.
 

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Isn't the connections between the ECU and the ABS unit just the four circuits?
395 (LGY = LF) on pin 1.
396 (LGS = RF) on pin 2.
397 (LGK = LR) on pin 3.
398 (LG = RR) on pin 4.

I do not see a CANbus or serial communication connection on the wiring diagram that I have (Elise North America 05MY, Sheet 14).

If these ECU connections are just a low-side PWM for each of the ABS when the ABS unit is powered, when either or any/all of these inputs (395 - 398) are pulsed, what happens?
The Elise manual says the isolation valves are normally open (NO), while the dump valves are normally closed (NC).
If these are low-side PWM inputs, then are these activating the dump valves ... and since the ABS unit is NOT in an ABS-active mode, fluid is free to flow from the Master Cylinder inlet to the caliper, expelling any trapped air in the ABS valve body and accumulator?

I have not tested, but will shortly, if when the vehicle is on, that circuits at pins 1-4 (395-398) are at 12V (system voltage).
If they are, then I think the vehicle ECU just has a set of low-side coil drivers that are PWM'd while the brake system is pressurized and allows brake fluid to flow from the master to the calipers.

I can imagine a low-pressure bleeder tank connected to the master, the caliper bleed ports opened, and one evokes a PWM to each/any/all of the ABS inputs and fluid will flow while pulsing the dump valves.

How the ABS unit's pumps operate, me think is solely within the ABS micro, and has nothing too do with the Lotus ABS-unit brake flush routine.

I'd love to get my hands on a few (free) ABS units to test this out.
Connect directly to a powered ABS unit (unplugged from the vehicle).

Else, these lines are simple voltage inputs to the ABS unit, and a given analog voltage is used to evoke a flush routine within the ABS unit. yet, I suspect not as that would be subject to EMC issues and deemed unsafe.

If this is the case, just need a PWM input, we have a 12 - 24V a system controller with multiple low-side PWM (and proportional valve) than can easily perform these tasks.


any further insight into this ABS unit, which I understand is the same used in the 90's Ford Aerostar van ... will be appreciated.
 

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Discussion Starter · #11 ·
395 (LGY = LF) on pin 1.
396 (LGS = RF) on pin 2.
397 (LGK = LR) on pin 3.
398 (LG = RR) on pin 4.
Those are your wheel speed pulses sent from the EBC to the ECU - the ECU uses those to calc the speedo value (for the CAN dashes) and the slip rates for the TC.

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You want to look where Pin #12 from the OBD connector goes to - it is Splice H and that goes off to the ABS/EBC and SRS/Airbag controller.

Rectangle Font Parallel Pattern Symmetry



So far i can tell that when you enable the ISO valve the foot pedal is ISOlated - you can build up pressure with the pedal, when u then release the ISO valve you make a nice mess on an unconnected brake hose. (i cleaned it off all kinds of parts afterwards ;-) The PUMP alone doesnt do anything with the the ISO/DUMP valves as far as i can tell, it only seems to be "enhancing" the pedal action. I will only have my rear calipers on in a couple of weeks, when i do the actual bleeding i will test more.
 

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Thanks, I missed that splice H on sheet 3.
So there is a communication channel to the ABS unit.

What is this "vendor option" communication? Kline? I suppose so.

If it were a CAN message (PDO or SDO) ... then I'd expect to see a CAN-H and CAN-L connection on the ABS unit and I could code these messages.
If a one-wire serial, I can't as the system controller only has CAN. :(

The connection on the ABS unit's pin 20 goes to the gauge, and appears to be the ground signal for the ABS icon/light.
 

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thx for the offer, but i need the CAN part for my T4e's - i will probably end up doing a PCB that can do CAN and K-Line (so far i have em separated) - it is just hard to find a proper OBD2 cable that has all pins on the DB9m and i didnt really look hard for a pcb edge solder connector - making a dongle + 3d printed case would be sweet.
If I had enough time, I would take this case from aliexpress. I have already some, they are really cheap and everyone can order them. ObdDiag.net also use them, so we already have the PCB size.

1288401


Then I would re-use the CANable schematic and firmware. It works great with few components, just need to add small stuff to add K-Line and L-Line:

1288402


It would be fun to make a special Lotus Adapter ;-) For now I use my VAG-Cable, a CANable adapter glued in a OBD-Case and a OBD Y-Splitter.

For info: Your can2usb adapter based on Arduino loses packet on T4e with old firmware like "BCroftT4E070 01/11/2005 Lotus EngV0078" or "BCroftT4E080 20/02/2006 Lotus EngV0080". Those old firmware send data constantly loading the CAN-Bus at 100%. It's seems to be corrected on newer firmware. The CANcable with the candlelight firmware handle this 100% CAN-Bus load correctly.

Next challenge is the Airbag controller ;-)
I've heard that the Opel tool OP-COM works with the Lotus Airbag... If true, we just have to analyze the communication. I cannot say, I do not have any airbags.
 

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Discussion Starter · #16 ·
If I had enough time, I would take this case from aliexpress. I have already some, they are really cheap and everyone can order them. ObdDiag.net also use them, so we already have the PCB size.


For info: Your can2usb adapter based on Arduino loses packet on T4e with old firmware like "BCroftT4E070 01/11/2005 Lotus EngV0078" or "BCroftT4E080 20/02/2006 Lotus EngV0080". Those old firmware send data constantly loading the CAN-Bus at 100%. It's seems to be corrected on newer firmware. The CANcable with the candlelight firmware handle this 100% CAN-Bus load correctly.

I've heard that the Opel tool OP-COM works with the Lotus Airbag... If true, we just have to analyze the communication. I cannot say, I do not have any airbags.
might order some, and i found something on OBD2-Shop.eu | Fahrzeugdiagnose Diagnose OBD OBD2 OBD-2 OBD II OBDII - bit more space, i really like the esp32+wifi, much more power than the atmega - alternatively a pic32 - memory is factor because at least one flash page should be cached for efficient flashing.

@drops - the can2usb is really bad yes, the little cpu is bit a stretched on that task and windows serial handling doesnt help either.

Yes i also found the OP-COM, and i have a Airbag Reset Tool from some shady internet corners that is asking to be unpacked and reversed (can reset crash dump data). protocol seems to be KW81 - the hardware above should be able to handle it, maybe i find a cheap crashed one i can do some testing - so far my airbags are ok.
 

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I recently installed SS Brake Lines and am currently trying to bleed the ABS system. I got the initial bleed completed using an EEZI Bleed with no air observed. Brake pedal is very soft and requires double pumping to get pressure. I'm going to try to induce the ABS system under hard braking, in a controlled area, and re-bleed. If I can't get that to work, the nearest dealer is a 3hr drive each way... Would be great to have something like the OP!
Diamond cut tar before repaving has been magic in its abiliry to get air bubbles out of my steering rack. Maybe that could help the ABS bubbles
 

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I ended up driving 3hrs each way to nearest dealer. Only took the Tech 45min and I provided the brake fluid. Brakes are working better than ever!
 
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