Transfer Case with LSD in it but ACD not working
 

Hey all

Who knows stuff about the ACD system and what not?

Currently my ACD is dead. goes into fault mode due to no ABS. Says fault 65 which is the handshake error between abs ecu and ACD computer. Ive removed the ABS ecu completely and re routed the speed sensors etc to try sort but didnt work. grounded the pin etc and still get the fault.

So im considering just not using the ACD at all. If i just fill the ACD up with fluid and leave it in fault mode so it is essentially "open" would this mean the front axle becomes open regardless of the fact i have a wavetrac lsd? I know if i had a stock diff it would be open. but wouldnt the LSD overcome this? or do the clutch packs being released essentially stop all drive to the RH axle regardless of what type of diff is installed?

Just trying to work out my best options here. Considering removing the ACD all together, Wiring the pump so its constantly engaged ( but told this is bad idea cause u dont want it engaged during cornering?) or making up some sort of system to try trick the ACD ecu into thinking that the ABS computer is there by simulating the 0.5v signal. or just leaving it in fault mode and "open"

I think the IX RS came with ACD and no ABS. I would copy the wiring scheme of that particular model if possible. Using the ACD function can be very beneficial on the track. ER can flash the ACD module, but i'm not sure if removing faults is an option in those flashes. It can't hurt to ask though.

yea i might flick ER a PM on here. i facebooked them but didnt hear back. Be good to get my hands on that wiring schematic. ive only been able to find one generic GSR one on google. Hopefully u can reflash and remove the Comms handshake from the software

The ACD is the center diff. Hence "aCD". It has no effect on the front diff. You are now operating with a completely open center diff. If you plan to not use ACD I would get a VCU (viscous coupling) Tcase.

Okay i see so what effect does having an open center diff have on the car overall? Bearing in mind i have LSD front and rear

Open center diff SUCKS! Its pretty obvious when you race with on cause the car will hit a terminal understeer on power or snap oversteer and the only way to catch it is resettle the car and try again. Basically one end gives up and thats it. Even with the VCU its slow to respond but happens quick enough for a torque transfer to help things.

Open center is a terrible way to go.

im quite keen to find out if i can reflash the ecu at this stage!

I have a copy of the workshop manual with the wiring diagram if required. ACD without AYC I have just found.

PM me your email and I'll fire it over

Sweet will do now! I was just looking at EW_B aswell actually and it looks like i may need to simulate a resistance from pin49 on the 4wd ecu rather than sending it straight to ground. so instead of seeing 12v the 4wd ecu sees 0.5v

So i solved this!

with the help of a friend we designed and made up a circuit board which converted the 12v signal in to a .5v signal out and hooked it up to the acd to abs signal wire. Currently its on a switch which u have to select to on before turning ignition to on and then flick off again 10 seconds or so after starting. But will make an arduino based version that has its own inbuilt timer.

so long story short JDM spec evo 7s must require that .5v signal for a minimum of about 5 seconds and no more thM approx 60sec otherwise it faults. Interesting!

need to use the RS wiring if you want ACD with no ABS. Or you can take the ABS computer module and leave it plugged in but remove ALL other ABS stuff.

yup i did this initially but the ABS ECU ended up bricking itself haha.

We found the ACD computer needed to see an actual 0.5V voltage for between 5 and 60 seconds or it would fault on the JDM Spec so the RS wiring wouldnt have helped here i don think :(