ABS info on the ALDL

[eriks4]

For those that are interested in other data than just the ECU data from the ALDL, I just finished decoding the ABS bytes and added a graphical GUI that shows wheel speed, the status of the hold and release solenoids, the status of the pump and pressure switch and all 63 possible error codes. Only, it is an either / or thing. You can either receive data from the ECU or tell it to shut up and receive data from the ABS. Just did a testdrive, but still need to make an ABS stop.

I will test the new function for a couple of days after which I will update the espritmon on my website. Oh yes, while trying to send commands onto the ALDL to find the ABS I also got a response from the SIR, so that's next on the list. Attached is a screendump of the current ABS GUI.

Oh yes, it is the Delco System, so it will not work on the S4s and probably also not on the GT3.

[troutrou]

Wow, nice job ! You said Espritmon was not meant to be user friendly, but this ABS block diagram looks very nice !

I didn't know the ALDL plug was wired to the ABS, I thought (just assumed) the ABS computer was separate and had therefore its own diagnostic link.

It's cool/practical if the ABS can be queried from the same ALDL socket as the engine !

Your Software is getting better and better all the time, keep up the good work !

--

Vince

Edited June 22, 2009 by troutrou

[sailorbob]

Spooky I was just looking at this last night myself, I was going to use TunerPro v5 to handle the comms. Looks like I do not need to now Excellent work.

[lotus4s]

Why would it not work on an S4s?

[eriks4]

Yes, it might work. I think I recently saw an add for an S4s here that mentioned it had a Kelsey-Hayes ABS (which probably uses a different protocol). I just looked in the Lotus Service notes and it seems that the S4s still has the Delco Moraine system. In that case it would certainly work.

I just put the latest version with ABS connectivity on my website, so feel free to try it

[S4Esprit]

Pretty rad Erik! If you can figure out how to make it perform the solenoid bleed procedure - I'd be willing to pony up a few $$$!

[eriks4]

I certainly would like to implement such a feature. However, the only info I have on the ABS protocol is about mode 1, reading the data. I guess that to command the system to do something, similar to the ECU a mode 4 command would be needed. With the ECU there is some documentation that can be used as a starting point when reverse engineering the meaning of all the bytes in a mode 4 command, but for the ABS I haven't found such info yet.

[Jonathan]

Delco systems were on all the 4c cars apart from the late GT3 (98 onwards) and possibly very late S4s.

My 1997 GT3 has the Delco system.

[tinywillyuk]

Interesting piece of work!

I'm going to try this tomorrow to see if I can find out why my ABS kicks in when I brake even when not needed.

[Jonathan]

Erik - I wonder if you can use the wheel speed sensors to feed an traction control system - the harmonics off the wires I found were too 'dirty' lots of spikes etc fooling the reader.

Can't see it would really be that tricky.

Can't wait to try it out though (should get my own laptop really....)

[eriks4]

Jonathan,

What is unknown is the delay between the input from the wheel speeds sensors to the ABS computer and the time the ABS computer outputs the wheel speed on the bus. I'm not familiar wih the allowable sensor latency in input to a traction control system, but going through the ABS computer and then feeding it to a TCS will add some.