Disco 2, Immo & C/L problems

Mark XF · Mar 5, 2018

Hi there,

I have my first Landy, a 53 plate Discovery 2 TD5 Facelift, an MOT failure project vehicle I plan to put back on the road.

First issues I plan to deal with are electrical. Vehicle came to me with intermittent indicators, wipers etc and non operational central locking requiring EKA to disarm once immobilised. I started with the fusebox which showed evidence of corrosion once stripped. A service-able used replacement has so far as I can tell resolved most of the issues excluding the immo and c/l operating off a keyfob..

I have replaced the RF Receiver with a secondhand unit (on a very tight budget, violin music playing in background lol) hoping to eliminate that with no result.. Neither original or replacement showed any damage. Keyfob has new batteries and lights up when pressed..

Hoping not to have to splash out on a BCM rebuild as I'll have to save up for a while..

I have just read the excellent PDF by Neil White on here, I don't have Nanocom, but do have use of Autel DS808 which does seem to have some functionality with the BCM, doesn't seem to conclusively say if the RF signal is being received though. All advice appreciated

.

Thanks in advance, Mark XF

Hellastony · Mar 5, 2018

Mark,

Unless are absolutely 100% sure it works, I would be inclined to swap the RF receiver with a known good working one before trying anything else. If that doesn't resolve it, only then look elsewhere.

Tony

Mark XF · Mar 5, 2018

I have a feeling you're right Tony.. It's kind of feeling in the dark not being certain it works.. Though both modules appear undamaged internally with no evidence of corrosion, I have heard they are a frequent failure item.. looks like I may be saving up for a new one

wish there was a way to bench test it lol..

Many thanks,

Mark XF

sierrafery · Mar 5, 2018

Mark XF said:
but do have use of Autel DS808 which does seem to have some functionality with the BCM,

can you eventually set the alarm to "not fitted" with that tool? that would put you on the road untill you fix it

Mark XF · Mar 5, 2018

I'll have to look into that, I only hooked it up for the first time today. I've had mixed results with the DS808, it's a bit hit and miss on many vehicles. There wasn't anything in the BCU menu, but with Autel's quirky menu's it could be hidden somewhere else so worth me taking a second look... There was an option to program the key, but you have to press keyfob as part of the process and It didn't appear to be successful. Not having plugged it into a working D2 before it's difficult to know when it's behaving normally whilst going through the process.

I've also been studying RAVE for more information and it quotes the RF module is supplied with a 12v and when the keyfob is depressed, a 1000 baud signal is sent to the BCU... Checking the feed should be simple enough with a multimeter but I am wondering if an oscilloscope would pick up the signal across the feed when keyfob is pressed and prove the RF unit? A long shot but I'm tempted to have a go... Failing that, I'll be forced to save up for a new unit or at least a proven one as 'Hellastony' rightly pointed out.

Whilst I'm short of funds, I am lucky in that I do have some half decent tools to work with.. Mind you, Nanocom I suspect would beat the Autel here with it's hands behind it's back..

Meanwhile any more ideas greatly appreciated

I'm keen to rule out as much as I can.

Thanks again all,

MXF

Moron · Mar 5, 2018

I have a similiar immobiliser problem.......I have to hold my key up close to the reciever in the headlining for it to switch off the immobiliser...........both my keys are the same,
Yes I've renewed the key fob batterys
I have also fitted a new receiver in the headlining and that made no difference

Mark XF · Mar 5, 2018

I tried holding my remote close to the receiver with no result, but something i tried unsuccessfully but might help you being that yours kind of works is the bolt that earths the unit...

One of the bolts holding the receiver to the roof contacts a plate on the receiver that acts as an earth reference.. To rule it out as a problem, I cleaned the bolt with a wire brush and cleaned the threads of the hole it locates into.. I wonder if you aren't getting a good earth if it would reduce the effective range of the receiver.. Stabbing in the dark here but might be worth a go?

Good luck, Mark XF

sierrafery · Mar 5, 2018

Mark XF said:
the RF module is supplied with a 12v and when the keyfob is depressed, a 1000 baud signal is sent to the BCU... Checking the feed should be simple enough with a multimeter but I am wondering if an oscilloscope would pick up the signal

Yes, you should be able to check the receiver's output with oscilloscope if you know how to us it

Mark XF · Mar 5, 2018

Sierrafery, it will be interesting to find out

, I used to use scopes years ago, but haven't a while.. A few months ago I bought a cheap PC based scope on offer which I have been looking for an excuse to use.. When I next get a chance to work on the landy, think I'll give that a shot. It'll be educational if nothing else

Thanks,
Mark XF

brian47 · Mar 5, 2018

Mark XF said:
Meanwhile any more ideas greatly appreciated I'm keen to rule out as much as I can.

@neilly has done a pretty good write up on the security system on the D2 which you can find at:-
https://www.landyzone.co.uk/land-rover/handy-buying-alarm-info.311291/
If nothing else it could give you some ideas. Remember, while the vehicle is immobilised, no diagnostic code reader will be able to communicate with any ECU, for security reasons.

Moron said:
I have a similiar immobiliser problem.......I have to hold my key up close to the reciever in the headlining for it to switch off the immobiliser...........both my keys are the same,
Yes I've renewed the key fob batterys
I have also fitted a new receiver in the headlining and that made no difference

The usual problem which causes low range of the RF receiver is either a poor earth connection to the receiver or moisture ingress. The earth connection must be absolutely clean and tight.

Moron · Mar 5, 2018

brian47 said:
The usual problem which causes low range of the RF receiver is either a poor earth connection to the receiver or moisture ingress. The earth connection must be absolutely clean and tight.

I'll give the earth a good clean , thanks for the suggestion

brian47 · Mar 5, 2018

@Mark XF, @Moron.
I'm sorry guys, my last message didn't post correctly. I have repaired it now.

sierrafery · Mar 5, 2018

Mark XF said:
Sierrafery, it will be interesting to find out , I used to use scopes years ago, but haven't a while.. A few months ago I bought a cheap PC based scope on offer which I have been looking for an excuse to use.. When I next get a chance to work on the landy, think I'll give that a shot. It'll be educational if nothing else

Thanks,
Mark XF

Unfortunately i wasnt curious enough to see the waveform with oscilooscope cos i have testers so a 100% relevant result would be only if you get no output from the RFR while the fob is pressed cos if you get it might be trunkated which you will not know if it's good for the BCU or not... worth a try anyway

Mark XF · Mar 5, 2018

Good point, I'll hope I get lucky...

Having read up more on RAVE, I think I might get the cover off the steering column as well and check the passive remobilisation coil.. Thing is, when changing the fusebox, I noticed a multiplug sticking out from the bottom of the column cover and nowhere obvious to connect it.. Previous owner did take landy to a garage because they were having issues with it becoming immobilised randomly.. Not sure what happened at this stage but wondering if for some reason coil was disconnected and that's the multiplug I can see sticking out.. Seeing as that communicates with the RF Module, I guess if so, no chance it would disarm.. But then, if that was so, would it still start with the EKA (it starts and drives fine once EKA entered) All I know is from that point onwards they just left it unlocked...

It's another longshot but I didn't know about this coil at the time and just thought it was a redundant plug.. Feel a bit stupid to be honest not having investigated this earlier......... question is, if I'm right, will the original fault return or if I'm really lucky maybe the fusebox I've now replaced was the original problem.. I can only speculate till I have another look now but it's something else I can look to..

Thank you everyone for your suggestions, everything has been useful and I have quite a few new directions to go in before I need to think about the BCM..

I will let you all know what happens next..

Many thanks, Mark XF

brian47 · Mar 5, 2018

Mark XF said:
Sierrafery, it will be interesting to find out , I used to use scopes years ago, but haven't a while.. A few months ago I bought a cheap PC based scope on offer which I have been looking for an excuse to use.. When I next get a chance to work on the landy, think I'll give that a shot. It'll be educational if nothing else

Thanks,
Mark XF

Almost all 'scope probes are high impedance, so correctly connected it shouldn't affect the circuitry. The receiver, if I understand the system should receive the "modulated" or pulsed RF from the fob, remember it's not just sending a plain RF signal, but it will contain the fob security code.
The output from the receiver to the BCU should then be a set of pulses at as you say 1000 baud which will be a digital representation of the fob security code. That set of pulses would then be passed to the "comparison circuits" within the BCU and if they match then the security circuits will operate. If no match is found then nothing will happen.
Having worked with such signalling (Arinc, the system used in the civil aviation industry), you will probably be unable to create a readable trace on the 'scope, you might see some trace disturbance but not be able to read anything sensible, well not without a storage 'scope.

Mark XF · Mar 5, 2018

Being PC based, I think it can act as a storage scope of sorts but as a low end model I'm wondering how hard it will be to make any sense of the data.. I would settle I think for now with just getting a real time reaction to the keyfob being depressed from the module.. I can try the old module too... If nothing else it will be educational.. As you will see from my post above, I may have overlooked something else rather basic that I'll eliminate first.

I have to say I am very impressed with the feedback I'm getting from you all.. I used to play around with electronics when I was younger and have played a little since in most basic form (Arduino and the likes), I will enjoy getting a chance to learn more and combine these skills with some of the more mechanical aspects of this project landy.

I just wish I had more time to spend on it..

Thanks again, Mark XF

sierrafery · Mar 5, 2018

Mark XF said:
Having read up more on RAVE, I think I might get the cover off the steering column as well and check the passive remobilisation coil..

The information in RAVE can have some lacks from time to time, in reality the passive coil has nothing to do with the alarm cos the passive immobiliser disables the security code to the engine ECU if the fob - receiver communication is already failed and doesnt let the engine to be started if the receiver doesnt get the signal from the fob which is triggered by the coil but the engine will crank while the main immobiliser which kicks in with the alarm will disable the starter too.

Mark XF · Mar 5, 2018

It's certainly not a basic system, I can see how without nanocom or similar the diagnostic process becomes somewhat complicated

.

From fresh with the battery first re-connected, the starter is disabled, the immobiliser in operation. If I lock and unlock the door, the alarm will sound. The remote doesn't have any response and the only way to disarm the system is by inputting the EKA.. Once the EKA is entered and I have waited the 5 mins, the vehicle starts and all is well unless I lock the vehicle in which case I am back to square one lol..

The main problem is having so many unknown variables to eliminate.. I am now satisfied the fusebox is OK.. I GUESS it's IDM is successfully communicating with the BCM, the mileage displayed is correct, but I'm not experienced enough to even be totally aware of any consequences this replacement IDM may have on the disarm sequence. By correcting one fault, I could be causing another

.. I haven't seen anyone have issues like this with changing the fusebox though so touch wood this is not the case..

It's like a game of 3d chess lol..

Thanks again,

Mark XF

Mark XF · Mar 6, 2018

Had 5 min just now and out of curiosity popped bottom steering cover off.. The random multiplug was not to do with the coil, in fact was leading up to column, I would guess for cruise control when fitted? Good to know that it shouldn't be plugged into anything though..

I think a play with the oscilloscope will be next on the cards lol

All the best,

Mark XF

Mark XF · Mar 6, 2018

Had another bit of play.. With a multimeter between each wire to the rf unit and ground respectively, I get over 13 volts... So, power getting to rf unit... Further, hooking up my cheap and nasty velleman scope between ground and one of these wires gave me a waveform of a few millivolts pretty much a squarewave, only had a quick go so no real data yet.. What was interesting is that on pressing a remote button, the waveform changed enough to lose trigger and some kind of different signal was generated.. I want to try and record the data and get some more data, the software is very basic so that's another project... But, I think I can now ascertain that.

A. The key is successfully sending a signal to the RF unit (I didn't feel completely confident that just because the led on key flashed that all was well here)

B. In some extent the RF unit is capable of receiving the signal from the key.

From herein I guess that either the key is not fully programmed or synchronised to the vehicle, or the BCU is not correctly accepting the signal from the RF unit..

I know that the autel showed 2 out of 4 key slots contained data for a key, the vehicle came with 2 keys, one with the remote pretty much fubar, so I only have one to work with.

As has been so rightly pointed out, I still can't conclusively say that just because the RF unit is receiving the signal from the key that it is fully operational.. I don't know how much it interacts with the BCU or the remobilisation coil.. From RAVE, it sounds like a two way communication, is this due to the rolling code system?

Perhaps without nanocom i just won't be able to pinpoint this. I'm not sure where best to next invest money or time in this investigation.

Thank you everyone for your help so far and if you have anything to add, I'll be most grateful

All the best,

Mark XF

Disco 2, Immo & C/L problems

Member

Active Member

Member

Well-Known Member

Member

Well-Known Member

Member

Well-Known Member

Member

Well-Known Member

Well-Known Member

Well-Known Member

Well-Known Member

Member

Well-Known Member

Member

Well-Known Member

Member

Member

Member

Similar threads