Disco 2 5 ACE DTCs Logged and leaking fluid in the rear

Hi Guys,

Firstly I need to apologise as I posted this in Introduce Yourself to begin with, I'm still getting used to using this forum!
I'm new here and I'm looking forward to getting to know people on here! I've been a life long fan of LRs but I'm fairly new to owning LRs and have had my 02 Discovery 2 for about 8 months.

And now my ACE system has seemed to start giving up on me, I got the Red ACE light on when driving home from work the other night, so I got under the thing after getting home and found there was a fair amount of fluid surrounding the rear ACE Strut/Actuator and had obviously blown on to surrounding areas whilst being driven. I've inspected hydro lines and haven't found any damage thus far but I'm not going to rule it out just yet.

Are there any other common things that go wrong these systems?

Here are a few pictures for context:









I'm aware that this looks like a lot of fluid that been blown onto the other components and I plan on washing off as soon as I can, but I'm hoping this just looks worse than it is because I do still have fluid in the reservoir.



I then plugged my Hawkeye Diagnostic into it and it read 5 ACE related DTC codes from the BCU, which are as follows:

DTC 13
NO ENGINE SPEED SIGNAL RECEIVED.

DTC 18
CLOSED LOOP PRESSURE NOT UNDER CONTROL.

DTC 20
VALVE BLOCK CHARACTERISTICS OUT OF SPECIFICATION.

DTC 33
DIRECTION CONTROL VALVE FAULT.

DTC 41
THE SYSTEM PRESSURE HAS BEEN BELOW A THRESHOLD FOR A TIME, WHEN A PRESSURE HAS BEEN DEMANDED.

I also ran the ACE system test function in my local Lidl car park (as the test requires a level surface) and the results were as follows:

Direction Valve 1
36ms
ON TIME (Should be 15-60ms)

Direction Valve 1
1020ms
OFF TIME (Should be 15-65ms)

Direction Valve 1
1020ms
SYSTEM TIME (Should be 100 - 260ms)
_______________________________
Direction Valve 2
44ms
ON TIME (Should be 15-60ms)

Direction Valve 2
968ms
OFF TIME (Should be 15-70ms)

Direction Valve 2
1020ms
SYSTEM TIME (Should be 100-250ms)
______________________________
Pressure Valve
100ms
ON TIME (Should be 4-50ms)

Pressure Valve
196ms
SYSTEM TIME (Should be 25-115ms)

(Please note; I have written all these results down directly from the Hawkeye).

I have seen that you can replace these systems with just standard non-ACE anti roll bars but I'd like to avoid doing that if at all possible.

After looking though a couple of threads on here I have decided temporarily stopped using the vehicle but as its my only method of transport I really need to get it back on the road ASAP, so any advice to to help keep me on the road whilst I sort this out would be very much appreciated!

But any help with this situation is very welcome!

EDIT:
I've just read about Relay 14 under the bonnet as a temporary fix on another thread and will try that to start with!

Hi , that system test with miliseconds is not relevant, first of all clear all those codes then go for a short ride and read codes again cos some might be hystorical, or if one is current it will not clear... removing R14 will reduce the leak but for diagnostic bridge the thicker cavities in the fusebox(where the relay's contact goes) then read live data at idle with hawkeye and post them here and the fault will be revealed. Can you see serious activity in the tank at idle ? ... btw, top it up

sierrafery said:

Hi , that system test with miliseconds is not relevant, first of all clear all those codes then go for a short ride and read codes again cos some might be hystorical, or if one is current it will not clear... removing R14 will reduce the leak but for diagnostic bridge the thicker cavities in the fusebox(where the relay's contact goes) then read live data at idle with hawkeye and post them here and the fault will be revealed. Can you see serious activity in the tank at idle ? ... btw, top it up

Click to expand...

Hi Sierra,
Thanks for the advice, you were right about the historical fault codes. The only fault showing up now is DTC 18 - CLOSED LOOP PRESSURE NOT UNDER CONTROL. I've watched the live data for a little while at idle like you said and this is what it was reading:
Engine Speed - 719RPM
Upper Lateral Acc - Between -0.06G and -0.012G
Lower Lateral Acc - Between 0.22G and 0.27G
Direct Control Valve 1 - 0.02 AMPS
Direct Control Valve 2 - 0.01 AMPS
Pressure Control Valve - Between 0.06 AMPS and 0.11 Amps
Pressure Sensor - 15 to 16 BAR
Residual Pressure - Between 2.88BAR and 3.30BAR
System Pressure - Between 2.78BAR and 4 BAR

I've recorded these as accurately as I could as some values jumped around a bit. I also haven't seen much activity in the fluid tank.

Will I be okay topping it up with PAS fluid? or is there a specific ACE fluid I need?

Use cold climate fluid, slightly green

The rears appear to be leaking a little as the pressure is very high. I would clean all the dirt off and look if the weep is then obvious.

About £300 in bits to repair using same method, or convert as follows

If not leaking at block consider cutting pipes off near the block leaving plenty to get 3/8" pipe 1/4" BSP compression fittings

2x 3/8" compression fittings, 2m hose, 14mm banjo.

4 ACE washers 2 ACE bolts.

This is cheapest repair.

I converted mine nearly 5 years ago but converted block to use BSP fittings with 4 ram hoses and short adaptor hoses to pump pipes.

02Big_Rig_Disco said:

Upper Lateral Acc - Between -0.06G and -0.012G
Lower Lateral Acc - Between 0.22G and 0.27G
Direct Control Valve 1 - 0.02 AMPS
Direct Control Valve 2 - 0.01 AMPS
Pressure Control Valve - Between 0.06 AMPS and 0.11 Amps
Pressure Sensor - 15 to 16 BAR
Residual Pressure - Between 2.88BAR and 3.30BAR
System Pressure - Between 2.78BAR and 4 BAR

Click to expand...

here are values retrieved from a well working system:
ACE INPUTS
1. DCVs (both) - .001A
2. Pressure control valve: 0 - .012A
3. Pressure sensor: varies between 16 and 19 but if it's out of that range the transducer is gone
4. Residual pressure: between 3 - 6 Bar but can be higher after the vehicle was driven or the ambient temp is low
5. System pressure: around 6 Bar fluctuating
6. Accelerometers: 0.01

So first suspect is the pressure transducer and for the accelerometers you have to run a calibration but you should fix the leak first cos that can mix up the readings as well. As long as there is serious activity in the tank with engine running and it doesnt get empty you can drive it with relay removed to minimize the leak untill you fix it

for transducer see this http://www.discovery2.co.uk/ACE_transducer.html