Ace amber warning light on

sierrafery said:

Are you sure that the readings are kOhm not Ohm?, those readings are far out of what should be ... anyway you'll have to do some gymnastics to crawl under, unplug the 3 solenoids on the valve block then read again from C0647 same pins with C0391/0377 connected and diconnected ... for C0377 insert a needle into the cavities and measure on that

Click to expand...

I have ordered some smaller needles that are coming tomorrow, I’ll do it again tomrrow to double check, the range on my reader is automatic, but it says in the corner (k) or (m) on all of these reading is was showing,
I will do it all again tomorrow with the needles, and will update you tomorrow

Ok untill then i'll explain you as simple as i can why these readings are nothing like they should be, i edited the part of the diagram which is relevant( DCV = directional control valves, two on the top of block, PCV = pressure control valve on the side)
on the left side of diagram from C0377 the wires ar going ro C0647 , the pins as follows:
2 -> 24,
8 -> 22,
14 -> 23,
7 -> 25,
13 -> 27




So if C0391/0377 and C0647 are all disconnected then the readings at 0647 shoud be 0 as both ends of the circuit are in the air and with 0391/0377 connected 0647 should be connected to the DCVs and PCV through 0391/0377

The resistances of good solenoids must be as follows: both DCVs = 2.5 Ohm, PCV = 5.5 Ohm (+/- 0.5 is acceptable) so that's why your readings are so strange, the Ohm selection must be the lowest on your mulimeter

does this make any sense for you ?

sierrafery said:

Ok untill then i'll explain you as simple as i can why these readings are nothing like they should be, i edited the part of the diagram which is relevant( DCV = directional control valves, two on the top of block, PCV = pressure control valve on the side)
on the left side of diagram from C0377 the wires ar going ro C0647 , the pins as follows:
2 -> 24,
8 -> 22,
14 -> 23,
7 -> 25,
13 -> 27


View attachment 204069

So if C0391/0377 and C0647 are all disconnected then the readings at 0647 shoud be 0 as both ends of the circuit are in the air and with 0391/0377 connected 0647 should be connected to the DCVs and PCV through 0391/0377

The resistances of good solenoids must be as follows: both DCVs = 2.5 Ohm, PCV = 5.5 Ohm (+/- 0.5 is acceptable) so that's why your readings are so strange, the Ohm selection must be the lowest on your mulimeter

does this make any sense for you ?

Click to expand...

Yeah mate that makes sense. Let me get my new needles tomorrow and I’ll check it all again and update you on my findings

sierrafery said:

Ok untill then i'll explain you as simple as i can why these readings are nothing like they should be, i edited the part of the diagram which is relevant( DCV = directional control valves, two on the top of block, PCV = pressure control valve on the side)
on the left side of diagram from C0377 the wires ar going ro C0647 , the pins as follows:
2 -> 24,
8 -> 22,
14 -> 23,
7 -> 25,
13 -> 27


View attachment 204069

So if C0391/0377 and C0647 are all disconnected then the readings at 0647 shoud be 0 as both ends of the circuit are in the air and with 0391/0377 connected 0647 should be connected to the DCVs and PCV through 0391/0377

The resistances of good solenoids must be as follows: both DCVs = 2.5 Ohm, PCV = 5.5 Ohm (+/- 0.5 is acceptable) so that's why your readings are so strange, the Ohm selection must be the lowest on your mulimeter

does this make any sense for you ?

Click to expand...

Just to clarify tho mate I’m still just testing the pins you said in the earlier post, and in the order you said, unplugged / plugged in etc

You have to do what i said here https://www.landyzone.co.uk/land-rover/ace-amber-warning-light-on.353360/page-2#post-4827257

sierrafery said:

You have to do what i said here https://www.landyzone.co.uk/land-rover/ace-amber-warning-light-on.353360/page-2#post-4827257

Click to expand...

Morning mate, right I’ve read the instructions for my multi meter, it says it automatically finds the range,
So I just set it to auto and read the connectors,
The results are all over the place, but I’ve double and triple checked them,
So here goes, I hope I don’t make this sound to complicated:
Reading from C0391 - Ace block ( DCV’s and PCV still connected)
2-8 0.022 ohms
2-14 0.023 ohms
7-13 1.135 ohms
Reading from C0377 to unplugged C0647:
2-8 open loop
2-14 open loop
7-13 open loop
With C0391/C0377 reconnected reading from C0647:
24-23 135.0 (k) ohms
24-22 137 (k) ohms
25-27 25.8 ohms
Disconnected C0391/C0377 reading from C0647
24-23 open loop
24-22 open loop
25-27 open loop
I then reconnected C0377/C0391 and disconnected the PCV and DCV’s
Reading from C0647:
24-23 8.00 ohms
24-22 open loop
25-27 23.5 ohms
I then disconnected C0377/C0391 ( still with DCV’s and PCV disconnected, I was reading from C0647 still:
24-23 open loop
24-22 open loop
25-27 open loop
Still with PCV and DCV’s disconnected, I’m reading from C0391:
2-8 open loop
2-14 11.0 (m) ohms
7-13 25.0 ohms
I have no idea mate but I triple checked all the figures and made sure I tested every which way I can, hope this helps thanks

Seems very like the loom between C0391 and valve block is chaffed somewhere or your multimeter is fubar, at what voltage is it working?(i mean what battery(s) has in it) ?... make somehow and hook the probes into 0391 across each pair at a time and watch the multimeter while you jiggle the loom along the reachable parts and see if the reading is jumping or not

sierrafery said:

Seems very like the loom between C0391 and valve block is chaffed somewhere or your multimeter is fubar, at what voltage is it working?(i mean what battery(s) has in it) ?... make somehow and hook the probes into 0391 across each pair at a time and watch the multimeter while you jiggle the loom along the reachable parts and see if the reading is jumping or not

Click to expand...

9 v is the battery size I will do some more testing mate we will get to the bottom of this haha

Megamagelol1 said:

9 v is the battery size I will do some more testing mate we will get to the bottom of this haha

Click to expand...

sierrafery said:

Seems very like the loom between C0391 and valve block is chaffed somewhere or your multimeter is fubar, at what voltage is it working?(i mean what battery(s) has in it) ?... make somehow and hook the probes into 0391 across each pair at a time and watch the multimeter while you jiggle the loom along the reachable parts and see if the reading is jumping or not

Click to expand...

Right I’ve done a bit more digging, I’ve been unplugging the pressure transducer not the PCV,
I unplugged it as 7/13 are the connectors giving me a bad reading,
Once unplugged it gave me a open loop reading! I think this means there’s something wrong with my pressure control valve ? Would you agree

The only good readings untill now were
Reading from C0377 to unplugged C0647:
2-8 open loop
2-14 open loop
7-13 open loop
Disconnected C0391/C0377 reading from C0647
24-23 open loop
24-22 open loop
25-27 open loop

cos these
Still with PCV and DCV’s disconnected, I’m reading from C0391:
2-8 open loop
2-14 11.0 (m) ohms
7-13 25.0 ohms
should all be open loop and with solenoids connected 2-8 and 2-14 should be close to 2.5 Ohm and 7-13 close to 5.5 ... eventually measure the resistance directly in the solenoid's plugs if you can reach the pins

sierrafery said:

The only good readings untill now were
Reading from C0377 to unplugged C0647:
2-8 open loop
2-14 open loop
7-13 open loop
Disconnected C0391/C0377 reading from C0647
24-23 open loop
24-22 open loop
25-27 open loop

cos these
Still with PCV and DCV’s disconnected, I’m reading from C0391:
2-8 open loop
2-14 11.0 (m) ohms
7-13 25.0 ohms
should all be open loop and with solenoids connected 2-8 and 2-14 should be close to 2.5 Ohm and 7-13 close to 5.5 ... eventually measure the resistance directly in the solenoid's plugs if you can reach the pins

Click to expand...

Right mate I’ve got a spot on reading (5.5) on thePCV after swapping it out ( the solenoid) only to then realise that it was heavily corroded, I’m still getting a bad reading on both DCV’s I’ve narrowed it down to 3/4 wires,
2-8
2-14
Going to c0377/c0391
So I’m guessing a bad wire under body,
Is there any way of narrowing it down further ?

If you hook the multimeter to those pins and start squeezing the loom along it's reachable sections and if you see jumps on the reading there's the area of the fault... unfortunately these kind of wiring issues are a nightmare, if you dont find anything visible better redo the circuit... just confirm you dont get open loop on those circuits with DCVs unplugged? ...if that's the case check for corrosion in those plugs

sierrafery said:

If you hook the multimeter to those pins and start squeezing the loom along it's reachable sections and if you see jumps on the reading there's the area of the fault... unfortunately these kind of wiring issues are a nightmare, if you dont find anything visible better redo the circuit... just confirm you dont get open loop on those circuits with DCVs unplugged? ...if that's the case check for corrosion in those plugs

Click to expand...

Yeah messuring up from underneath the car. Of both DCV plugs. To a unplugged
Co377/c0391 if giving me a high ohms reading so I’m guessing more broken wire than corroded plug,
I will squeeze along it tomorrow, if not I will crimp a new sure onto wire 2,
After the join.
If I get a good reading I can narrow
Down the fault,
But only if I don’t find it by squeezing it,
I will
Keep you posted mate but you have been a massive help and I’ve learnt so much more !! I can now use the wiring diagrams and everything thanks so much mate

Keep up the good job m8 cos you are on top of it as you found the reason why the system doesnt work just that you'll have to figure out how to fix it... i presume it became clear to you that for the system to work you have to get 2.5 Ohm on the solenoids pins and the same reading on C0391 across 2-8 and 2-14 with solenoids connected, the same like it happend with the PCV... if you dont find the chaffed wiring better route a multi core wire from the valve block to C0391 and redo the whole circuit cos it's not a big deal.

sierrafery said:

Keep up the good job m8 cos you are on top of it as you found the reason why the system doesnt work just that you'll have to figure out how to fix it... i presume it became clear to you that for the system to work you have to get 2.5 Ohm on the solenoids pins and the same reading on C0391 across 2-8 and 2-14 with solenoids connected, the same like it happend with the PCV... if you dont find the chaffed wiring better route a multi core wire from the valve block to C0391 and redo the whole circuit cos it's not a big deal.

Click to expand...

Yeah mate it didn’t really make sense at first but the more I thought about it and the more you explained the clearer it became,
Now I know what we’re trying to achieve, I can say for sure now that by tomorrow evening there will be no ace light illuminated! thanks so much for all the help and no I know how to test resistance ill be coming back for more info!
how do you know firstly what ohms are required by each control valve ? Is there a website to tell you that? And also where do you get the diagrams from? Like the one from the ace block? I’m interested in getting a test rig set up like you have

Megamagelol1 said:

how do you know firstly what ohms are required by each control valve ? Is there a website to tell you that? And also where do you get the diagrams from? Like the one from the ace block? I’m interested in getting a test rig set up like you have

Click to expand...

I know the resistances of solenoids as i measured not one myself even bran new ones...these figures are not shown in any document, as about the diagrams you can find them in RAVE where you found the electrical library for the connector views, all the systems are covered there's the "Workshop manual" too which describes all the systems and operation modes, the ACE is within the "Front suspension" chapter, second part (only LR knows why) ... check it out as a bedtime reading ... i was exactly like you 13 years ago when i bought the D2 and knew nothing about it then i've learned everything on my own with hard study(all i knew then was electronics)

if you dont have the fully working RAVE i'll attach you PDF links

This has been interesting.

Please note two types of block with different solenoids, latest version look similar to the RRS and D4 blocks.

I have been trying to find a source of JUST the late coils but no luck as yet.

The resistance of the coils is within the same range regardless of the slight shape difference cos they have to work with the same ECU, also i measured both types to confirm.

MJI said:

This has been interesting.

Please note two types of block with different solenoids, latest version look similar to the RRS and D4 blocks.

I have been trying to find a source of JUST the late coils but no luck as yet.

Click to expand...

That’s another thing I learned I have an earlier block so that was why

sierrafery said:

The resistance of the coils is within the same range regardless of the slight shape difference cos they have to work with the same ECU, also i measured both types to confirm.

Click to expand...

Right I’ve been doing more digging this morning I cleaned the connectors up real good, I’m
Getting open loop from both DCV plugs back to co377,
The resistance on each solenoid plug is bang on both about 2.7,
From co377 down to the connectors I’m getting open ( when unplugged) how ever as soon as I plug them in I get a bad reading? Ive been trying to see if there any corrosion on the contacts on the DCV’s but there isn’t and no visible corrosion on inside of plug? Any thoughts mate