Disco 2 ACE Fault 20-04

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mad85

Active Member
Posts
503
Location
Malta
After changing front ram and ecu I now have a leaking valve block which I plan on fixing soon but also have this fault 20-094 Pressure Control Valve Fault.

Not sure what could be the cause of this but these are the inputs im getting when the amber light is off and on (it lights on after driving a little while):

ACE INPUTS (Amber light OFF)
1. DCVs - 0.00A and .01A
2. Pressure control valve: 0.33A
3. Pressure sensor: 17.4bar
4. Residual pressure: 4.43bar
5. System pressure: 4.13bar
6. Accelerometers: -0.02 / 0


ACE INPUTS (Amber light ON)
1. DCVs - 0.00A and .01A
2. Pressure control valve: 0.64A
3. Pressure sensor: 0bar
4. Residual pressure: 3.8bar
5. System pressure: 0bar
6. Accelerometers: -1.42 / 1.42


any idea what could be causing this? is it just the leaking valve block?
 
You'll have to read inputs when the warning is on with bridged relay so when it comes on dont stop the engine, remove the ACE relay, make a bridge with a piece of wire instead of the relay's contact in the fusebox(the larger parallel cavities) and read inputs then. I'll tell you more after that cos a leak should not trigger a fault code as long as there is fluid circulating in the tank
 
the funny thing is that sometimes when i read the faults with the nanocom i get 'no faults' even though the amber light is on. sometimes i also get the fault i described when the amber light is not on! i know this is weird because as far as i understand the ace ecu is not able to store faults but rather tells you what is happening real time
 
I now got a new fault which caused the amber warning light to become red. Fluid is still up to the max and seems to be circulating normally

Fault 18-04 Hydraulic or mechanical fault in pressure control system

The inputs with relay bypassed are as following:

ACE INPUTS (Amber light ON)
1. DCVs - 0.00A and .01A
2. Pressure control valve: 0A
3. Pressure sensor: 14.28bar
4. Residual pressure: 20bar
5. System pressure: 2.5bar
6. Accelerometers: -0.01 / 0
 
The pressure is too low for some reason, te pump might not deliver enough or faulty pressure controll valve, or in the worst case a hidden wiring issue, unless it's the ECU.... at this point you have to make some troubleshooting if you know how, a simple thing is to measure the resistance of the PCV which is on the left side of block, it should have 5.7 Ohm
 
yeah ok, will check for resistances at the pcv, orange plug and ecu. im puzzled as i already changed the ecu 1-2 months ago, i hope it is not it again or i would think there is something frying the ecus somehow. could this be the transducer though? is there a way to test it?
 
The transducer's reading was good with lamp off but the pressure was low then too so it's quite unlikely to be that. I dont know a way to test the transducer other than replacing it
 
im remembering now, the garage who did the ram mentioned that they were adding a liquimoly power steering additive to try to get rid of the small leak at the valve block. to be honest im sure i have read people using this stuff without issues in the ace system, but could it have any bearing on my issue?
 
the garage who did the ram mentioned that they were adding a liquimoly power steering additive to try to get rid of the small leak at the valve block
:eek::confused::mad:SCHMUCKS
Leak stopper additive in the ACE????... :mad: that's the hugest bollox i've ever heard, IMO that mixed up the whole thing, that very fine filter in the block might be clogged with that stuff, additives are not conceived for a system which works above 130Bar, if the electrical side is OK you should remove the filter from the block and try to flush the system somehow then add the dedicated fluid

here's from the WSM, ACE repairs section

CAUTION: The ACE hydraulic system is
extremely sensitive to the ingress of dirt or
debris. The smallest amount could render the
system unserviceable. It is imperative that the
following precautions are taken.
l ACE components are thoroughly cleaned
externally before work commences;
l all opened pipe and module ports are
capped immediately;
l all fluid is stored in and administered
through clean containers.
 
That stuff just causes soft seals to swell and stop leaks. There are no such seals on the ACE system that i know of as its high pressure. The valve block uses the horrible plastic inserts. Id pull that block, strip it, tap it for hydraulic fittings and flush the whole system out. Then hope nothing else got knackered.
 
Yeah, i understand. Actually ordered a second hand block. Plan is i will fit the hydraulic fittings to it and then i just switch it. As the disco is my everyday car that would be my best option
 
Yeah, i understand. Actually ordered a second hand block. Plan is i will fit the hydraulic fittings to it and then i just switch it. As the disco is my everyday car that would be my best option


Good idea I did that
 
HI, Are these fittings good for fixing the ace valve block?

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s-l1600.jpg
 
I hope they do cause I just bought them :D

I was reading from another forum and a guy had done something similar and done a write up about it. this is a quote from it: "My first task was to find a place to purchase the compression fittings. The metal lines on the ACE system are 3/8. "
 
Yes they are 3/8, but 10mm olives/comp fittings will work and are cheaper. However, putting 3/8 bsp fittings into the block can be tricky as they foul each other unless offset. Some 3/8 fittings may have a smaller nut i dont know. I used 1/4 into the block then 3/8 hose on the main lines and 1/4 hose to actuators. Works fine. But 3/8 across the board for line and fittings is fine, just make sure you can get a spanner on the block fittings as they are close together
 
Yes they are 3/8, but 10mm olives/comp fittings will work and are cheaper. However, putting 3/8 bsp fittings into the block can be tricky as they foul each other unless offset. Some 3/8 fittings may have a smaller nut i dont know. I used 1/4 into the block then 3/8 hose on the main lines and 1/4 hose to actuators. Works fine. But 3/8 across the board for line and fittings is fine, just make sure you can get a spanner on the block fittings as they are close together

Same here
 
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