Disco 2 CDL upgrade - Electronics and TC control question

Hi all

My 2002 (i think) disco td5 did not come with cdl. The factory transfer case does not even have the nipple thing. As I had installed larger tyres, I decided to install a Transfer case with CDL from a defender TD5. So now I have CDL but the traction control does not know about it so will probably work against each other (if the traction control decides to lock 2 wheels on the same axle, for example).

What other modification would I need to get the traction control to know about the CDL being engaged? I was also thinking about doing a switch to switch off the traction control if I want to.

Please let me know
Mark

Hi. first of all make sure that the transfer case you fitted has the diff-lock switch on it, investigate above the tranfer case, if the wiring for the siwtch's input is there you should find two wires with female spade receptacles, connect them to the switch and lock the diff to see if you get the warning on dash or not..

there are few scenarios:
1.(the best) you find the wirning and the warning works
2.(not the best but still good) you find wiring but when you lock the diff you get a transmission high temperature warning
3.(the worst) no wiring at all

in case of 2 or 3 confirm which one and i'll tell you what to do, it's doable anyway no worries

if you dont have RAVE download and install disc 1 from here https://forum.club4x4.ro/showthread.php?56810-In-atentia-proaspetilor-posesori-de-land-rover cos you'll need the connector views

thanks for the reply. I did not install it myself, but asked a mechanic to do it. i think he did not connect any connectors and I do not get anything on the dash when i engage cdl.

will have to get under it and will let oyuo know.

thanks again
Mark

mad85 said:

Hi all

My 2002 (i think) disco td5 did not come with cdl. The factory transfer case does not even have the nipple thing. As I had installed larger tyres, I decided to install a Transfer case with CDL from a defender TD5. So now I have CDL but the traction control does not know about it so will probably work against each other (if the traction control decides to lock 2 wheels on the same axle, for example).

What other modification would I need to get the traction control to know about the CDL being engaged? I was also thinking about doing a switch to switch off the traction control if I want to.

Please let me know
Mark

Click to expand...

how can they work against each other,both axles will be driven at the same speed ,both wheels couldnt spin faster than the other axle, a wheel can only spin faster if the other is stopped or slowed and tc would come in there and try and equalise both wheels ,

I explained that few times and even experienced it myself as at the beginning when i didnt know anything about D2 i followed a tutorial to cut the difff-lock input wire to the SLABS to retain TC with locked diff and i lost motion in mud this way while after i studied deeply how TC works i understood what can happen so believe me or not there are cases when TC can come in conflict with the locked diff with pre-facelift SLABS, i think that's why even LR made it as to inhibit TC and ABS when the diff is locked and then asked wabco to upgrade the soft as TC to work together with CDL on facelifts which software was more updated on late 2004 modells

so the best setup is CDL + SRD500070 with wich the D2 is unbeatable no need for any axle locker

sierrafery said:

I explained that few times and even experienced it myself as at the beginning when i didnt know anything about D2 i followed a tutorial to cut the difff-lock input wire to the SLABS to retain TC with locked diff and i lost motion in mud this way while after i studied deeply how TC works i understood what can happen so believe me or not there are cases when TC can come in conflict with the locked diff with pre-facelift SLABS, i think that's why even LR made it as to inhibit TC and ABS when the diff is locked and then asked wabco to upgrade the soft as TC to work together with CDL on facelifts which software was more updated on late 2004 modells

so the best setup is CDL + SRD500070 with wich the D2 is unbeatable no need for any axle locker

Click to expand...

thanks for the detail. to be honest i did not experience it myself yet and would much rather fix it before it happens. tried to find the SRD500070 module but sounds like a hard to find item

mad85 said:

tried to find the SRD500070 module but sounds like a hard to find item

Click to expand...

i know... i treated myself with a bran' new one as one birthday gift for 5 years

search for SRD000150 maybe you have more luck cos that will work with the CDL as well

sierrafery said:

i know... i treated myself with a bran' new one as one birthday gift for 5 years

search for SRD000150 maybe you have more luck cos that will work with the CDL as well

Click to expand...

thanks! i will check what i have first and will move on from there

sierrafery said:

I explained that few times and even experienced it myself as at the beginning when i didnt know anything about D2 i followed a tutorial to cut the difff-lock input wire to the SLABS to retain TC with locked diff and i lost motion in mud this way while after i studied deeply how TC works i understood what can happen so believe me or not there are cases when TC can come in conflict with the locked diff with pre-facelift SLABS, i think that's why even LR made it as to inhibit TC and ABS when the diff is locked and then asked wabco to upgrade the soft as TC to work together with CDL on facelifts which software was more updated on late 2004 modells

so the best setup is CDL + SRD500070 with wich the D2 is unbeatable no need for any axle locker

Click to expand...

what instances?,early models had a disabled tc when diff lock engaged for service reasons ie removing a prop and running car in diff lock on brake rollers etc,what conflict can there be unless tc can only operate on one wheel at a time

Is there any way of updating the firmware of a module (without complete replacement)? my D2 premium ES was sold on 1st March so I’m assuming it missed the update mentioned above?

I'll try to find the thread where i explained this cos i couldnt untill now, i'm not gonna write the whole teory again... as i said i lost motion due to TC and locked diff and got out with TC disabled

jamesmartin said:

... early models had a disabled tc when diff lock engaged for service reasons....

Click to expand...

i reiterate that in RAVE is just a cryptic description of how the TC works, though if it's only for service reasons why it's not disabled on later modells too? ...anyway i dont want to argue on this eventually i can have a chat about how the algorythm is conceived to work based on the graphs from WABCO documents.

Spot1 said:

s there any way of updating the firmware of a module (without complete replacement)? my D2 premium ES was sold on 1st March so I’m assuming it missed the update mentioned above?

Click to expand...

No way to do that... maybe only wabco could cos it's not a ''flashable'' memory and needs hardware too

I knew i've had a ''deja vu'' Discovery TD5 52 plate centre diff lock untill the end

what i'm trying to say is that there are possible scenarios when TC + CDL can end bad, or some other cases when it can help... it's not a rule that always but for me is a proven fact that on pre-facelifts it's not a good ideea to not have CDL input to the SLABS

sierrafery said:

I'll try to find the thread where i explained this cos i couldnt untill now, i'm not gonna write the whole teory again... as i said i lost motion due to TC and locked diff and got out with TC disabled

i reiterate that in RAVE is just a cryptic description of how the TC works, though if it's only for service reasons why it's not disabled on later modells too? ...anyway i dont want to argue on this eventually i can have a chat about how the algorythm is conceived to work based on the graphs from WABCO documents.

Click to expand...

its not an arguement i want to see how this works, tc was disabled on early models due to service reasons, you had to remove prop and any rolling road work needs tc disabling

jamesmartin said:

... tc was disabled on early models due to service reasons, you had to remove prop and any rolling road work needs tc disabling

Click to expand...

i can't comprehend what has this to do with TC active action in the field ... and afaik that rolling road thing is valid for all not just for pre-facelifts

sierrafery said:

i can't comprehend what has this to do with TC active action in the field

Click to expand...

nothing,but i cant comprehend how cdl effects tc unless it can only operate on one wheel at a time

There are cases in the field when wheel speeds can be different on axle even with CDL, only the propshafts will spin together.... and yes, the TC can operate on only one wheel if that's the result of it's calculations

not sure if it is relevant, but mine is a facelift model...

It is. You said it's 2002 and facelifts were sent to the market in 2003 but it can be just a VIN thing... if it's facelift them most probably the SLABS is 000150 so the only thing you have to solve is the CDL input from the TB's switch

so, yesterday continued on my work and after i removed the center console, i found out that the black and blue diff lock wire from the harness is not connected to anything going to the transfercase. A close inspection of the underside, i also noticed that there is a black (ground) and black and green wire not connected to anything, just hanging near the gearbox. I know for sure that the wires originate from the same harness as the black blue wire. I also tried to short them but that did not light up anything on the dash. Was thinking about cutting the green black wire and splicing it in the blue black wire, so that I can use that, without having to pass a new wire. Question is ... anyone knows what that green black wire is for?