I think from your description that what is happening is that when you accelerate the power supply from the bcu via the xyz switch to the bcu and eat ecu is being interrupted, initially this causes the m+s lights to flash and the d display and d light to disappear and when you slow down the power supply resumes so the d display and d light reappear and start to flash.
The reason they continue to flash when the power is reconnected is that once a fault is logged in eat ecu and limp mode entered the eat ecu only resets once the ignition is turned off and not when the cause of the fault is corrected.
You could try to start off without the fault being present in gear position3, then 2, then 1and if the fault occurs in all positions then this would indicate that the fault is before the XYZ Switch.
 
I think from your description that what is happening is that when you accelerate the power supply from the bcu via the xyz switch to the bcu and eat ecu is being interrupted, initially this causes the m+s lights to flash and the d display and d light to disappear and when you slow down the power supply resumes so the d display and d light reappear and start to flash.
The reason they continue to flash when the power is reconnected is that once a fault is logged in eat ecu and limp mode entered the eat ecu only resets once the ignition is turned off and not when the cause of the fault is corrected.
You could try to start off without the fault being present in gear position3, then 2, then 1and if the fault occurs in all positions then this would indicate that the fault is before the XYZ Switch.
I can confirm it happens in every forward gear. The switch is only a few weeks old, and I initially thought it was the switch that was failing. Now though, I don't, because I am getting all the corrct lights and displays on start and tick over. I would also think then, that it's not a bad connection or a short to the switch, as the signal wouldn't be there at all. The fault will also happen if I put the lever in N and press the accelerator. I've looked at the area around the BCU, it's all very clean and dry in there. I have no leaks in the car, it's all dry. I keep wondering about the battery, will try some further checks on that today. I'm wondering if when the D2 is in a forward gear and the ECU is looking for a certain voltage, that pressing the accelerator is somehow altering that voltage to a higher than normal amount and then throwing up the fault.
 
I don't unfortunately. There is a 4x4 garage down the road from us. The owner is into his Landrovers. I have booked it in there for them to look at, but they can't look at it until Friday. Was hoping I might get to the bottom of it before then, but not looking good. Bit stumped.
 
I will relate my tale of woe and you can make your own mind up wether it relates to your situation.
Intermittent fault which caused m+s lights to flash, limp mode and disappearance of gear position light by selector and digital display by odometer, usually occurring after driving 20 miles in wet or 30 miles in dry conditions.
Fault logged, gear position monitoring.
Endless trips to garages, auto transmission specialists, Indy land rover experts and auto electricians who replaced, battery, xyz switch and electronic automatic transmission ecu without any lasting result.
I eventually bought a nanocom to try to sort it out myself.
I also did endless reading and searching threads until i had a very basic understanding of the xwy switch and associated circuits.
One day sitting in the car playing with the nanocom the fault occured ie m+s lights flashing but more importantly no digital display or light indicating gear position when selecting D,3,2,1 so I was able to look at the live reading of the wxyz feeds to both the bcu and eat ecus and low and behold there was no feed when selecting D,3,2,1, but P,R, and N were there when selected.
From previous reading I knew that P and N were an earth feed, R has its own feed from fuse 25 drivers side fuse box and D,3,2,1 shared a common feed from pin 10, connector 663 in the bcu.
After much persuasion my local auto electrician who had looked at the problem several times without success agreed to test pin 10 in connector 663 when the fault previously described was present and he found no live feed.
He took out the bcu which looked perfect, dry and no signs of water ingress and opened it, still no signs of damage so concluded that it was just an intermittent age related fault with the switch through which power was provided to the xyz switch circuit.
From previous research I knew that this switch was dedicated to the xyz circuit alone so he wired in a fix which cured the problem for several months until more bcu problems meant that I had to replace the bcu when I disconnected a fuse in the fix and have had no more problems.
To do what i did you would have to remove central console between front seats only.
The input feed path from the bcu to the xyz switch is as follows
N/P (brown / purple) 0.5 diameter wire throughout.
BCU - front passenger footwell
Connector 663 pin 10
Connector 668 pin 3 -main harness by handbrake
Connector 681 pin 3 - harness to xyz switch
Connector 675 pin 8 - to xyz switch.

The output path from the xyz switch for the input from the bcu is as follows
Z path
Connector 675 pin 6 UW 0.5 diameter wire
Connector 678 pin5 - harness from XYZ switch
Connector 728 pin 5 - main harness
Y path
Connector 675 pin 7 UG wire 0.5 diameter wire
Connector 678 pin 4
Connector 728 pin 4
W path
Connector 675 pin 9 UP wire 0.5 diameter wire
Connector 678 pin 7
Connector 728 pin 7
X path
Connector 675 pin10 UB wire 0.5 diameter wire
Connector 678 pin 6
Connector 728 pin 6

When D, 3,2,1 are selected the following wxyz paths are energised 12v positive

D W,Y,Z
3 X,Y,Z
2. Z
1 Y
If you havent got rave search for the following as pdf files and down load as they will help you
Discovery serries 2, workshop manual 1999MY on (VDR 100090 ENG (6) )
Discovery 2 MY99 to MY03 - Electrical library (LR0529ENG 3rd ED)
Discovery 2 Circuit diagrams 00MY RHD.

If you decide to investigate further and remove central console you will find by the handbrake lever the following
Connectors 681/668
Connectors 678/728
and with the information above you can check that the system is receiving power from the bcu and the xyz switch is transmitting power correctly when selecting forward gear positions,, bearing in mind that the fault which causes the digital display and light by gear selector to be absent, not just flashing.
 
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Wow. Thank you Roy, that is a wealth of information. I decided to get a new battery, even though the output of the old battery was good...ish. I've fitted it and driven 10miles or so. So far, so good. I'm not counting my chickens, but fitting a new battery has made a difference so far. I'll have to see how we go. Thanks to everyone who has helped me so far. I will update if the fault comes back again. I think it's a bit to early to tell if the problem was the battery.
 
Just thought I'd post a quick update again. Went out to the Landy yesterday morning and got the m and S lights straight away. After driving a little way and restarting, the fault remained. I was thinking the new battery probably wasn't fully charged, so drove on a bit more and restarted and it was all good. Drove on another 10 miles and checked battery voltage. 12.8 engine off 14.1 engine running. Left car for a couple hours and went for a walk around the coast. Came back to the Landy and all good. Travelled another 60 miles through the day visiting places around the Lizard and it was good all day. Hoping the new battery was just a bit low on charge, so will see this morning. Thanks again for the help and comments.
 
When this happened to me on day 1! in my Trusty old Peugeot.
Fourwinds Garage in Newquay where fantastic, lent me an old estate car to continue our holiday, stripped the engine, found it was not an easy fix ( Head cracked) advised me to join the AA. Charged me a very good price for the strip down and wouldn't take a penny for the loan car.
I joined the AA waited a couple of days and they took me home! Worth every penny.
Local chap to me got me a recon head and fixed it.
 
When this happened to me on day 1! in my Trusty old Peugeot.
Fourwinds Garage in Newquay where fantastic, lent me an old estate car to continue our holiday, stripped the engine, found it was not an easy fix ( Head cracked) advised me to join the AA. Charged me a very good price for the strip down and wouldn't take a penny for the loan car.
I joined the AA waited a couple of days and they took me home! Worth every penny.
Local chap to me got me a recon head and fixed it.
Luckily enough we now do have breakdown cover to get is home if needs be.
 
Ok. Thanks to everyone who contributed to help me out regarding this problem. I thought I'd post a final update as it may be of some help to others at some point. I'm glad to say we got home without any problems. Towed the van faultlessly and effortlessly. I now have no issues with the MandS lights and all seems well again. However, after fitting the brand new battery, on start up in the mornings, I would get the lights come up after selecting a forward gear. This happened even on the day we came home. As soon as I drove a little way, switched off and restarted, it would be fine for the rest of the day. Battery reading at the time was about 14.05 with engine running. After driving home on dual carriageways and motorways I tested the battery output the following morning after starting the engine. Has a nice steady reading of 14.57v. Drove off, no lights, no issues. Tested battery on return, same reading. It appears then, the new battery want quite fully charged and driving around Cornwall wasn't enough to boost the battery up to a full charge. In hindsight I should have put the battery on the caravan as it was on an electrical hook up, and the built in charger would have fully charged the battery, but never mind. I do read people putting new batteries on, which cures the fault, only to return the following day. New batteries may not be fully charged, and driving around may not always allow the alternator to fully charge the battery, given all the electronics on a D2, unless you take it on a long run up a motorway for a few hours! If you're battery output is around 14v with the engine running, it seems the signal to/from the xyz switch/BCU is likely to be interrupted with a drop in voltage, causing the M and S lights to appear. Make sure a new battery is fully charged, and don't assume driving around locally will create enough power to fully charge the battery either. Best idea is to fully charge the battery before fitting. Anyway, hope that may be of some help, but for now at least, the D2 is running well again.
 

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