Thread: Speedo Correction Clashing with ACE

Hey Mikey, maybe worth a try to recalibrate the ACE accelerometers with tester before you undo your circuit cos it might help(it can't hurt anyway)...they are calibrated from factory for standard tyres and a corresponding VSS for that, as the height of the car increased with bigger tyres but the VSS is modified by the speed corrector to be like with normal tyres it might be a missmatch and that strange symptom to occure cos as long as the accelerometers are higher the lateral acceleration will be different but the VSS is also different with bigger tyres and the ACE ECU can handle that, that's why it works OK without the corrector if you see what i mean

EDIT: if possible use Hawkeye or other dedicated tester for calibration cos IMO nanocom is a good tool just not the most reliable when it comes to ACE

if no joy with that(and provided the diagram in RAVE is good) and your corrector is serial setup(like the Superlift Truspeed i've fitted to a friend) then there's no place to splice in with the corrector as to avoid the ACE without making wiring mods cos the VSS from the SLABS(blue arrow in the diagram) goes directly to header C0290 from where it splits around to all the other components, the only points where you can connect with the corrector are as i said before at C0067 or before the instrument pack(red arrows)... there can be certain differences between the VSSs from one car to another and that's why for some a correction can cause issues for others not(i'm affraid to expose here my theory why but that's a fact)... there are many lifted D2 around the world but IMO a small percent have speedo correctors and they run without issues...so what you can achieve with your corrector without any issue is to see the true speed on the dash but if you want to addapt all the management to that except the ACE you have to bridge some wires there, worth a try with recalibration IMO ... see the diagram( it's from the RHD version of my RAVE which states "English" cos the "English export" variant is only for LHD, the circuit is the same only the pins at C0290 are different)

Thanks again to all who have posted, been a busy weekend so far! Have not had a chance to work on it with the rain and other happenings.

Sierrafery, one of the main reasons for the speedo correction is so the Auto gearbox operates as per normal/standard/real road speed and changes gear when it was designed to. The speedo showing actual road speed is a bonus. So I really need to have it connected before the auto ecu etc.

Hi Kelvo, I have used the post by SLUNNIE to initially setup and connect the speedo unit. Thanks again Slunnie, made it easy for me, I just did not expect to encounter any issues.

I also referenced The post by STEVO as he installed the same unit.

Sierrafery, I am not going to try and recalibrate the ACE accelerometers as it all works fine without the Ratio Interface in the circuit, with no strange behaviour.

Just to make sure I have it right guys, I Have the pink/green wire FROM the slabs ecu going to the BROWN wire(input) of the C6100 and the BLUE wire(output) of the C6100 connected to the pink/green wire that continues to the harness?

Maybe I am picking up some interference on the wires to the C6100 that is causing a glitch. I have the C6100 installed on the drivers side. I ran a figure 8 to the slabs ecu by following to existing wiring harness using a stiff draw wire. I might try running separate cores or split the figure 8 so the cores are not run exactly parallel to each other. Got nothing to lose.

I will report back when done. I will have to fit it in with all my other jobs (never ends ).

Cheers
Mikey

I couldn't see it detailed, has it been lifted at all? There can be an issue with the ace when lifted too far as the ACE arm angles downwards and alters its travel. There's been a thread or two on this and fixing (longer links) but couldn't find in searches.

MAYBE theres an issue with the travel/height/links during use that affects it but isn't obvious when static and not flexed?

Originally Posted by Mikey

Sierrafery, one of the main reasons for the speedo correction is so the Auto gearbox operates as per normal/standard/real road speed and changes gear when it was designed to. The speedo showing actual road speed is a bonus. So I really need to have it connected before the auto ecu etc.


I might try running separate cores or split the figure 8 so the cores are not run exactly parallel to each other. Got nothing to lose.

I will report back when done. I will have to fit it in with all my other jobs (never ends ).

Cheers
Mikey

AAAAhaaaa i didn now that, if that's your wish you can do a more simpler thing than you are up to, also nothing to lose cos you actually dont modify anything you just "reroute" the signal between the ACE ECU and SLABS as the corrector to be after the ACE: as you cut the KG wire from the SLABS anyway, cut the KG wire which comes out from the ACE ECU(C0647-5) and connect it where you connected the brown wire of your corrector.... job done, insulate the other side of the wire from ACE which goes to header C0290 and remember that you have a wire there with a corrected VSS in case if you need such signal for some other application

as per the calibration thing, it's normal for the ACE to work well without the corrector cos the accelerometers are a bit higher(that 2-3mm i dunno how much) but the VSS is a bit smaller with greater tyres but with the corrector the VSS will be like with standard tyres or even more accurate as there's a certain error with standard tyres too if you see what i mean...i told you about that cos this happened to a friend of mine and the calibration cured it

I suggest that ACE be disabled before any wiring changes so that you can test whether ACE is or is not causing the height change.

Originally Posted by Graeme

I suggest that ACE be disabled before any wiring changes so that you can test whether ACE is or is not causing the height change.

Best suggestion yet I recon. If you have a nanocom or the like, you can just turn the ACE on and off and see what effect it has.

Happy Days.

Just got home and checked in. Thanks for the suggestions guys.

I drove the D2 today to work and back and it appears the wiring changes I made had little effect as it is still misbehaving.

I do have a Nanocom 1....but someone else (whom, I took for granted, knew how to operate it) used it and decided to plug in an external power pack at the same time as being plugged into the OBD2 port. Guess what? They let the magic smoke out .

A track has blown and lifted off the circuit board.

Not sure if I have the skills to repair it. I will try though.

Regards,
Mikey

I recently discovered this old thread and thought I'd revive it because some weeks ago I installed my HUNTER Di speedo correction unit, and since fitting it I too have noticed abnormal behavior from ACE.
It's nothing like the OP experienced but it may furnish more clues towards understanding what's at play here. In my case I have an 85km drive to work every morning, the first half is fast open country driving until I encounter my first set of traffic lights. The road on the run-up to these lights has a slight right-hand curve and road surface camber slopes noticeably to the right at the stop line. If I'm the lead vehicle on the approach and must stop at the RED light, about 2 or 3 seconds after I have come to a halt, I feel a "nudge" behind me under the floor and the driver side of the D2 rises slightly and then gently falls, just onetime only.

I recalibrated ACE with my Hawkeye 10 months ago when the new tyres were fitted, it's worth doing again I think, and leave it at that, or I could re-wire and tap-in downstream so the SLABS ECU only sees the uncorrected VSS input.