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ACE Valve Unit Failure

FamilyGuy said:
Thanks greenmonster, I had looked at A1 but didn't know anything about them or if there was anybody in Bolton.

I know what you mean about one thing after another! I got stopped by the police yesterday because of the tinted windows on mine. I've also had a few other little problems:

Leaky windscreen
Leaky sunroof
Snapped rear wiper arm
Broken rear step
3 punctures - 1 of which meant a new tyre

All within 6 months of ownership.

I still love it though :)
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There is something of a "love to hate" relationship with these Discos isn't there? Can't quite put my finger on it, but it makes me smile when I look at it parked up.
Only had mine about 6mths (june2010): leaky sunroof fixed, took the roof lining out, sealed the roof bars as well only bolted on..not a bad job.
new rear wiper arm, cylinder head, top hose, powerbox upgrade, plus other bits/treats.
just wish I could drive it more than fix it :rolleyes:
 
I had a similar problem where the amber light kept coming on and it was a failure of the pressure transducer in the valve block. This is the one at the front of the block that can be changed without messing with the pipes. I was told by the nice man at Gigglepin was that cold weather could cause the failure. I have had it replaced and, touch wood, not had a worry since. Mind you I did worry in the recent cold weather. Cost of transducer is about £100 and I would guess 1/2 hour labour.
 
23skidoo said:
Well thats a interesting development . There is , for anyone who has trawled these forums for a while , a precedent for fuse box in the engine compartment suffering water or shorting out deterioration leading to all sorts of unexpected results . The fuse box IIRC (not near my TD5 to confirm ) is held in with 2 boilts at either end , maybe someone else here can tell you in the meantime . Undo them and Lift it out a bit and have a look undernear (where this normally occurs) to see if there are any signs of "damage" . If there is that may well be something that is causing your problem.
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Hi Skidoo,
Had both fusesboxes out of the car today..all connections clean and secure. Re-checked the red plug to ECM ECU and found a little oil on the red plug :eek:. All clean and dry now.
Also checked all the connectors on the ACE block, accelerometers and the ACE ECU. All clean.
Could not get the ACE ECU out from behind the glovebox, need to find my socket extensions and tackle this week, so I can find out the part number.
 
Whats the age of the Car , if its a very early one it will almost certainly be RQT100022 if its a very late one , then it will be RQT000030 . Its the no mans land in the middle I dont know about I think there was another ECU part number at one point . I suppose its really best to get the thing out to be sure .
 
23skidoo said:
Whats the age of the Car , if its a very early one it will almost certainly be RQT100022 if its a very late one , then it will be RQT000030 . Its the no mans land in the middle I dont know about I think there was another ECU part number at one point . I suppose its really best to get the thing out to be sure .
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Its a 2000 model. Just had a reply form a guy who has had the same problem. Turned out on his to be a contact in the engine bay fuse box.
 
Update - 10Feb..
TD5 back on diagnostics..hawkeye showed accelerometers were giving a signal, but couldn't obtain readings for pressure control valve or directional control valve.
Not a case of no readings...just could not find the options on Hawkeye. Old fault reported "road speed signal". This I believe refers to when ACE is activated (>25mph) as Urban as mentioned in previous post.

In the meantime, using the RAVE wiring diagrams, I've checked ALL the wiring connections for continuity...all report ok.
I'm stumped now... down to possible two components... accelerometer in the roof lining..this one reports faults to ACE ecu out of the two (when a fault happens)

or the ACE ECU itself... this reported no fault on diagnostics.

Just thinking if problem occured (because of cold weather...know how electronics can go mad in the cold)..then as its gone a little warmer..the fault has fixed itself...(would explain no fault found when checked at the garage) but because a fault has been recorded, the fault needs to be cleared to clear the light? Does this make sense? Don't know if the components are that smart..however hawkeye showed old faults..so maybe it remembers..
Will try and find a replacement ACE ECU...watch this space..
 
Finally got some diagnostics readings from Hawkeye.. tried a system test, but the residual pressure needs to be below 7.5bar. The system would not drop its stuck at 20bar. For those familiar with ACE...does this look like the ACE ECU has failed... the main relay will not turn on, I'm guessing the ACE ECU controls this, if my understanding is correct...still looking for a spare RQT100024 ACE ECU.

tests with engine running at idle car stationary
reverse switch not reverse
main relay off
warning lamp on
engine speed 720rpm
road speed 0
upper lateral accl - 1.43g
lower lateral accl -1.43g
direct ctl valve 1 = 0.01amps
direct ctrl valve 2 = 0.01amps
battery volts 0.03volts
press ctrl valve 0.02amps
press sensor 0 bar
residual pressure 20bar
system pressure 0 bar
ignition swtich on
 
Today42 said:
Well even more confusing, been on the road for a few days, had intermittent Amber light, then no light, with the light tending to be off more than on, then this am, had a Red Flashing light with audible warning. Stopped the car, restarted and everything seems to have cleared. So not sure what to think, although never know whatbtonexpect now every time I start her up.

Would welcome taking you up on the offer of having a look at the diagnostics, but am guessing will be no good unless I am in a phase of having one of the warnings on.
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Well since starting this thread, I have had the car hooked up to a Nanocom, kindly provided by Urban Panzer, a fault had been recorded in the pressure transducer, he managed to reset it and all seemed fine. Now for the last couple of days, get an intermittent fault Amber or sometimes RED light, which seems to clear every time I stop and start the car. Sound like a dodgy connection perhaps??
 
Dont know what the D2 handles like with ACE but mine has been removed during previous ownership and reverted to ordinary rollbars.I can say that I dont find any problems when pressing on and doing a bit of spirited cornering on A or B roads and I dont treat it with kid gloves to start with cornering.
 
Today42 said:
Well since starting this thread, I have had the car hooked up to a Nanocom, kindly provided by Urban Panzer, a fault had been recorded in the pressure transducer, he managed to reset it and all seemed fine. Now for the last couple of days, get an intermittent fault Amber or sometimes RED light, which seems to clear every time I stop and start the car. Sound like a dodgy connection perhaps??
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Might well be a dodgy connection. Having continuity tested all my ACE wiring, I can tell you that the earth point is in the lower A-pillar in a multblock. Think you might need to stick it on nanocom or hawkeye to be sure. My ACE ECU is reporting no faults, but the accelormeters are out by miles and there is little volts (see the readings on my last post).
take a look at this post : https://www.lrukforums.com/showthread.php/193431-ACE-Amber-Warn-Light

Think 23skidoo may be onto something.
 
greenmonster said:
Finally got some diagnostics readings from Hawkeye.. tried a system test, but the residual pressure needs to be below 7.5bar. The system would not drop its stuck at 20bar. For those familiar with ACE...does this look like the ACE ECU has failed... the main relay will not turn on, I'm guessing the ACE ECU controls this, if my understanding is correct...still looking for a spare RQT100024 ACE ECU.

tests with engine running at idle car stationary
reverse switch not reverse
main relay off
warning lamp on
engine speed 720rpm
road speed 0
upper lateral accl - 1.43g
lower lateral accl -1.43g
direct ctl valve 1 = 0.01amps
direct ctrl valve 2 = 0.01amps
battery volts 0.03volts
press ctrl valve 0.02amps
press sensor 0 bar
residual pressure 20bar
system pressure 0 bar
ignition swtich on
Click to expand...


That looks very familiar .. I would say its ECU that is either Toast or has got itself into some sort of unrecoverable fault state.
 
Today42 said:
Well since starting this thread, I have had the car hooked up to a Nanocom, kindly provided by Urban Panzer, a fault had been recorded in the pressure transducer, he managed to reset it and all seemed fine. Now for the last couple of days, get an intermittent fault Amber or sometimes RED light, which seems to clear every time I stop and start the car. Sound like a dodgy connection perhaps??
Click to expand...
Today42.. just out of interest I rang TD5alive on another issue. In passing, mentioned about ACE...they have had several TD5's over winter with warning lights on..some of them self fixed! Might just be the cold weather altering the fluid viscosity and causing problems. Worth a thought before spending more to fix it.

I'm still looking for a replacement ACE ECU...
 
Update: 22Feb.
Replacement ACE ECU arrived today. My old one is RQT100024, this replacement is RQT100022.

Fitted it...and problem fixed!!!!!!! :D:D:D:D:D:D:D thanks 23skidoo you guessed correctly.

No need to calibrate anything..just swapped out the ACE ecu.

Going to take the old one apart..to see if there is a way to repair them.
 
congratulations - its weird how discos are so complicated and yet sometimes such an easy fix ! - i guess they tried by design to segment off each section of electrickery. how much was the ecu out of interest ?
 
greenmonster said:
Update: 22Feb.
Fitted it...and problem fixed!!!!!!! :D:D:D:D:D:D:D thanks 23skidoo you guessed correctly.
No need to calibrate anything..just swapped out the ACE ecu.
Going to take the old one apart..to see if there is a way to repair them.
Click to expand...

Thats great news . I keep meaning to open one up .. never find the time . I suspect the fault will be ether inside a chip and therefore not something visible or software , i.e the Firmware burnt on the thing (which have a hunch is the case) . Its a forgone conclusion the chip is not buirnable , its probably a rather academic excercise As it was never a big scale fail point , and not until after "reasonable" service life , probably never got as far as a Tech Doc at LR , but there may be a boffin who has the goss on it , dont hold out any hope of ever getting those beans spilt.

If you do open it up and find a blown fuse or nice dry joint or something .. do let us know. :)
 
Well..took the ACE ecu apart..not much inside, half the box is empty space. The bottom half has a circuit board similar to a graphics card in it. 3 capacitors on the board, none of which show signs of swelling/failure. The whole board appears to of been dipped in a rubber solution/coating to waterproof it. I'm going to leave the unit without power for a couple of weeks to let the capacitors discharge. might try plugging it back on the car after this, but I doubt it will fix it. There's no serviceable parts inside, no fuses either.
 
Hello,
My name is César and I'm from Chile. I have a Discovery 2 V8 MY2004 with ACE and since a couple of month ago I'm having problems with the ACE System. Sometimes, on hot days, when I'm driving slow, the ACE red light turn on with a lot of ping ping ping... for a some minutes. When I turn off and turn on the vehicle, the ACE light dissapear.
This week I receive my new Hawkeye and it found 3 fault codes in the ACE System (I connect the Hawkeye with teh ACE red light on and the engine running):

DTC: 48 Main Relay Fault. Logged Fault.
DTC: 33 Direction Control Valve fault. Logged Fault.
DTC: 41 The system pressure has been below a threshold for a time, when a pressure has benn demanded. Logged fault.

I already changed the pressure transducer but the problem don't disappear... Now I', going to drain the ACE fluid and change it for the Land Rover STC50519 (I think my Disco have another hydraulic fluid because it doesn't look like the STC50519...). Do you know if I could made some service to the Control Valves? Or you think that my problem is whit the ACE ECU?

When the system is on fail, I have similar reading that Greenmonster:

"
tests with engine running at idle car stationary
reverse switch not reverse
main relay off
warning lamp on
engine speed 720rpm
road speed 0
upper lateral accl - 1.43g
lower lateral accl -1.43g
direct ctl valve 1 = 0.01amps
direct ctrl valve 2 = 0.01amps
battery volts 0.03volts
press ctrl valve 0.02amps
press sensor 0 bar
residual pressure 20bar
system pressure 0 bar
ignition swtich on"

But when I turned off and on the engine, the readings change and appear to be OK.

Do you have any idea about what could be the problem?

Sorry for my English but I'm trying to improve...

Regards!
 
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