Hello,


My disco 2 (TD5 2001) has had the amber ACE light on for quite a while now.

I’ve got a couple of weeks off work, so would like to get the issue sorted. I’ve done some searching about but no one else seems to have the same issue.


Basically, the light goes out when the disco is started (as it should), it stays out until I go round a left hand corner, I can go round right hand corners all day long and the light stays off.


I plugged it into my nanocom a while ago and it came up with about 10 fault codes, all of which wouldn’t clear. Also, the nanocom would not perform any of the output functions, i.e. force main relay on, or turn light off or open DCV valve 1 or DCV valve 2. It seems like it will not communicate with each other.

I was told at the time it was the ACE ECU, so I replaced this with a known working unit. Still the light came on, but only a couple of fault codes now exist. All of these fault codes through the nanocom will not clear, therefore they must be persistant faults. Also I am still unable to perform any communication between the nanocom and ACE system. I cannot open any valves or re calibrate anything.


These are the faults shown on the nanocom:


1. Upper and lower accelerometer signal too different


2. Upper accelerometer Zero G position out of range


3. Road speed signal missing


Now I tried to calibrate the upper and lower accelerometer through the nanocom, but nothing changed or happened. Again, no communication between nanocom and ACE


Here is the data that I can see on the nanocom about the ACE system at idle engine speed:


Engine speed - 720 RPM

Road speed - 000

Battery Voltage - 000.02

DCV1 current - 000.00 Amps

DCV2 current - 000.00 Amps

PCV Current - 000.00 Amps

Pressure - 000.00 Bar

Residual Pressure - 020.00 bar

System pressure - 000.00 Bar

Upper accelerometer - -01.42 g

Lower accelerometer - 1.42 g

Ignition - ON

Reverse - NOT REV

Main relay - OFF

Warning lamp - ON


Can anyone tell me if these figures are anywhere near correct?

I know the accelerometers are way out, as the system only reads -1.10 g to 1.10 g, so i dont understand how they are reading past this value?


Is it simply a case of changing the accelerometers or is there some other issue with the ACE system that is not letting me communicate with it?

Hi, better not rely on nanocom when it comes to ACE, if you really want to fix it find somebody with other tester(hawkeye, lynx, autologic or T4)... you'll not be able to fix this based on nanocom readings believe me, though from my experience nanocom used to be a bit more reliable on live readings than fault codes so based on those it seems that there's no supply through the main relay, make sure that fuses F15 engine bay and F29 interior fusebox are good, if yes swap relays R14(ACE) with R13(horns) and see if the horns are working... if yes again remove R14 and put a bridge instead it's contact (terminals 30-87, concentrate to not put it elswhere) then read live data again to see if you get different readings or not... though even if one of these tricks will help you'll not be able to properly calibrate the system with nanocom whatsoever

Thanks sierrafery. I will give that a try and let you know what happens. Do you know of anyone in the Sheffield / peak District area that has a hawkeye / lynx or anything else apart from nanocom that I can borrow in exchange for beer tokens? To try and work out what the issue is

Thanks