Disco 2 Forum Newbie: Problem with Limp Home Mode Activating on a D2 TD5 Auto

[JoyB24]

Hi Everyone! Newbie on LandyZone and just finding my way around it Think I posted this query in the wrong forum yesterday so am going to try again. We desperately need advice on what to do about the ongoing problem with our beloved 99 Reg TD5 D2 Auto otherwise known as 'Big Red'. I don't know anything about the technical side of Land Rovers but my husband Rod does and he is stumped. As he doesn't do computers etc but I do you will have to put up with our double act where Rod tells me what to write about Big Red's problem and I put it on the Forum and hopefully if anyone can help he can then read the responses and act on them.
THE PROBLEM: The regular activation of LIMP-HOME Mode with the two green Manual and Sport Mode lights flashing simultaneously! This problem has plagued us for years(we have had 'himself' for 10 years now)
A fault code is always stored on the auto transmission ECU each time the limp home mode is activated. These fault codes have subsequently been cleared by the various people including a main dealer who reckoned that they were going to cure the problem. The D2 then behaved normally for a while until the fault recurred. If we switch off the engine the lights will mostly have gone when we switch back on again.
Most recently we visited a specialist gearbox repairer who confirmed that there are no active faults within the gearbox itself. The specialist suggested that they replace the starter inhibitor switch which is situated on the n/s of the gearbox and is connected to the central console gearbox selector knob. We agreed to this and a reconditioned one was fitted last October 2015. For a time all was well and we were lulled into a sense of false security(Do Discos do this to their owners on purpose?) Then just after Christmas the dreaded lights appeared again. Just now and again to begin with and always disappearing when the engine was switched off and on again. But this am we tried, unsuccessfully, to clear the lights three times. Seems to happen mostly when starting from cold.
Since 2013 we have installed a new heavy duty battery, had a replacement BCM(water ingress problem), replaced the injector wiring harness(in case any oil leakage could have affected any electronic components)
We hope that someone out there on the Forum recognises this problem and has a solution - short of scrapping Please help if you can.

 

[jamesmartin]

id replace the xyz switch on lhs f gear box which is what they called the inhibitor switch, sounds like youve replaced a poor one with another poor one

 

[JoyB24]

Thanks for replying Do you think that replacing it with a new ie not recon inhibitor switch would rectify the problem. We were prepared to pay for a new switch but they suggested this allegedly recon one instead and said it would be OK.
Think we will go to a reputable main dealer for the new one probably should have in the first place. Oh well you live and learn
When we went back to the specialist and said limp home was being activated again they said that there were lots of other possible reasons not just the inhibitor switch!!!! but didn't actually do anything to rectify it. Hence our plea for help.

 

[jamesmartin]

switch did work for awhile didnt it ,in that the symptoms went ?

 

[JoyB24]

Hi again Yes for about 3 months. So we will try putting an actual new Land Rover part on and fingers crossed. Will post again when we have put the new part on. Thanks for your help really appreciate it.

 

[shaun69]

Hi again Yes for about 3 months. So we will try putting an actual new Land Rover part on and fingers crossed. Will post again when we have put the new part on. Thanks for your help really appreciate it.

Just be sat down when they give you a price lol

 

[JoyB24]

Well we already know what the cost will be but it will still be painful!! However at least they will have to guarantee their work

 

[ROY SIMPSON]

Well we already know what the cost will be but it will still be painful!! However at least they will have to guarantee their work

I have a similar problem. Do your lights on the gear selector and display in the instruments ie D etc flash or disappear altogether. Mine disappear and a new genuine LR xyz switch has not solved the problem nor several trips to land rover specialists and auto electrician.
Have now bought a nanocom to try to diagnose the problem but sods law it won't happen while plugged in.

 

[JoyB24]

Thanks for taking an interest in our D5 problem. Sorry for the delay in replying - busy weekend!! In answer to your question no, none of the lights you mention behave like that on our D5. Basically a mode called Limp Home keeps being activated which is signalled by the two green Manual (M) and Sports Mode (S) lights flashing. Sometimes it can be persuaded to come out of Limp Home Mode by switching off the engine leaving for 60 secs and switching back on. We were advised to have a new Starter Inhibitor switch which worked for about 3 months and now the problem has started up again worse than ever. I am inclined to think that another Forum Member who has replied has the right idea. The reconditioned switch which was installed was dubious in quality and has just given up the ghost again so tomorrow Tuesday Big Red is booked into a main dealer in Lincoln who has done good work for us in the past for diagnosis and assessment -- so wish us luck folks Will let you all know what transpires

 

[sierrafery]

The secret lies in the stored fault code cos there are 15 possible reasons for limp mode even though the XYZ switch is the most common... there must be a
"P0705 * Gear position switch incorrect outputs" code stored in the ECU for the switch fault to be 100% confirmed or you'll replace the switch in vain if it's let's say for example
P0753* Shift solenoid (MV 1),open or short circuit code or one of the other 13 codes instead if you see what i mean

 

[JoyB24]

Hi sierrafery
That's really depressing but hopefully a good main dealer will be able to tell us what the real problem is and hopefully sort it out once and for all or is that being too optimistic??????? Have to hope its not something major in the autobox Do some of the codes mean easily rectifiable faults? or are they all bad news???

 

[sierrafery]

All are fixable, actually a solenoid would be cheaper than the switch and they used to give intermittent faults

 

[JoyB24]

Hello Again - you mean there is hope fingers crossed for tomorrow -will post the outcome tomorrow night hopefully Thanks for your help.

 

[stew laws]

Mine was coming up with the intermittent M&S .. I done a filter and oil change first as it was on the cards ( 3 Rd change on a 90 k motor ) not convinced by a fluid change and no filter, doesn't make logical sense.
Anyhow my problem is solved, coincidence?? .. Time will tell but the xyz switch isnt always the way though and the cost is a bit high to be clutching at first point of call.

 

[sierrafery]

... hopefully a good main dealer will be able to tell us what the real problem is....

that's what concernes me ...cos most main dealers are schmucks IMO

 

[stew laws]

Have a friend who is a autoelectrician .. He has a section of racking he calls the 'honesty shelf' a place he puts bits on when he has misdiagnosed a problem, he counted up £3000 of spares, he admits he does make mistakes, but he does not pass it on to the customer, a rare breed amongst garages who seem to guess a bit too much at the expense of its customers..
Not all I grant you, but we all know it's a common occurrence

 

[JoyB24]

Hi There
That's always the worry - how good is the main dealerthe one we are going to today has done good work for us in the past at a reasonable price and they are willing to spend some time on an older Disco and take it seriously - quite unusual☺ Anyway will report back tonight maybe with good news!!!Appreciate the interest you are all showing☺

 

[JoyB24]

Hi Folks
Good news at last - our TD5 'Big Red' will live to fight another day The problem is not in the Autobox - the engine and injector looms have become badly contaminated with engine oil which has managed to get past a seal into the ECM and cause it to send garbled info to the other computers that it communicates with that Land Rover have scattered about Discos. one of these is the computer which controls the autobox and when it receives info it can't make sense of it puts the autobox into 'Limp Home' mode hence the flashing lights 'just in case'. They did full diagnostics and checked various other bits as well and then decontaminated the engine loom and ECM which should cure the problem temporarily. They are sending us a quote to sort it out by replacing the injector and engine looms, seals etc and are confident that that will cure the problem. They had given us a fixed price of £64 + VAT for the diagnostics and that is what they charged us. They do special fixed prices for older Discos so I think 'Big Red ' will be going there next week. Hope this info is of some use to at least some of the members who posted about their flashing lights - check the ECM for oil contamination Sorry if this explanation is not technical enough but its the best I can do Hope the lights and 'Limp Home' stay quiet until next week but as I said they seemed pretty confident!!

 

[sierrafery]

I wish you good luck and i dont want to ruin your joy but my oppinion is that this is not the real issue here... IMO you can let the engine ECU submerged in oil and it will not create autobox limp mode, the problem is not the oil there but the bad contacts at the injector solenoids which would throw injector fault codes... a wiring issue on the main harness would give that symptom provided the fault code stored in the autobox ECU was CAN related, just ask them what was the fault code cos you are on the way to be ripped off IMO... i hope i'm wrong and all will be good but i have serious doubts though...we'll see

 

[iansoady]

I would strongly recommend buying your own diagnostic reader - either Hawkeye or Nanocom. They do take a bit of learning and are not cheap but as you're finding you can throw huge amounts of money at the car by changing things without getting at the underlying problems.

Sierrafery knows (almost) everything about the electronic systems of these vehicles and I would trust his opinion. But until you actually know what fault codes are appearing and have seen them yourself you're dependent on people whose ability is unknown. Even main dealers are not necessarily familiar with 10+ year old Discoveries.