Disco 2 TD5 Transmission Problem

[disco2tas]

Hello,
Hoping someone can help with this.
2001 Disco 2 TD5, 253,000kms with immaculate service history.
M&S lights started to flash recently but had no effect on trans.

Yesterday while driving the trans went into Neutral and engine speed dropped to idle, there was no response from pressing the accelerator, engine remained at idle.
Drifted to a halt, the M & S lights were flashing, tried moving the trans lever to different positions with no effect. Turned off the engine, restarted and all worked as normal. But this occurred another 7 times.

Had a scan tool plugged into it but gave very odd fault codes

012C. CAN message MD_IND invalid, (flag F_TL_MES)

C021. CAN message WFPDK (DK1) invalid (FFA)

Both stated "Not present, intermittent fault, not requesting MIL.
Any help would be greatly appreciated.
thanks
Alan

[nismine01]

The problem lies with the (what I call 'inhibitor switch'), I think it's called XYZ switch on side of gear box.
Drivers manual says 'if they come on pull to side of road, switch off motor then restart.
The switch gets dirty/wet and fails, sometimes intermittently sometimes constantly and you are stuck in a sort of 'limp home' mode.
Replace the switch with a known good one and you'll be right.

Cheers

Mike

[bsperka]

Check for oil in ecu connector. Oil in connector causes CAN faults and leads to flashing M&S lights. See http://www.aulro.com/afvb/showthread.php?p=1796599 as to why. Or use other posts on that thread.

[bsperka]

The problem lies with the (what I call 'inhibitor switch'), I think it's called XYZ switch on side of gear box.
Drivers manual says 'if they come on pull to side of road, switch off motor then restart.
The switch gets dirty/wet and fails, sometimes intermittently sometimes constantly and you are stuck in a sort of 'limp home' mode.
Replace the switch with a known good one and you'll be right.

Cheers

Mike

Not when you have a CAN fault indicated. CAN isn't used for much in D2 but isn't around the auto position ('xyz') switch.

[sharmy]

Mine was doing the same thing soon after i purchased it in 2008. I took it back to the dealer to be fixed and was told it was a loose soldered joint on top of the box. They re-soldered it and it has not given any problems since.

John

[AllTerr]

Do you have a CDL fitted? Mine did the same thing as well. Turned out that I had shut the engine down with the dif lock engaged and had to engage it back and forth a couple times to turn lights off.

[disco2tas]

Thanks for the very useful replies.
When the fault originally occurred it was in bad traffic situation so was not fully able to assess the symptons.
Have since tested in quiet area with no traffic and was able to get the fault to repeat very often.
Main thing determined is the transmission is ok. What happens is the engine speed drops to idle, there is no response from accelerator, pull over and still have drive from the trans but only at idle. It will go from forward to reverse ok. The MS lights flash and MIL illuminates, turn off engine, restart and all works well again, but drive a few hundred metres and fault repeats.
Previous owner had a similar fault where the engine was cutting out, among other things that was replaced was a known good accelerator pedal, but that did not fix the fault, eventually another engine ECU was fitted which fixed the fault.
We are suspecting faulty wiring, or as has been suggested oil in the ECU.
Will be tackling this again on Sunday, trying to find faulty wiring is going to be a fun job.

[bsperka]

I know that Allfourx4 replace the engine harness if the m&s lights come on, due to the age and oil issues, plus injector harness. Can you post up the issue / fix when you find it ? It should be added the m&s thread.

[bsperka]

From http://forum.landrovernet.com/showth...-gearbox-fault

*"It turns out it was a fractured earth return wire for switch status signals, from the gearbox back to the control unit - is that the ECU?. The fracture formed a high resistance return path and when that happens - like trailer electrics with 'flashing' brake lights and dimming flashers - the ECU becomes confused, although sometimes movement will temporaily reduce the resistance and allow a brief period when it works.

I understand the earth connection was on top of the auto box, beneath the centre console trim. A simple matter to fix, but probably quite tedious to get at."

[disco2tas]

Well we spent a couple of hours today testing circuits, in particular beteen accelerator & the ECM, could not find any faults.
The wiring diagrams on Rave has an oddity for the accelerator wiring, it shows terminal C on the ECM plug connecting to terminal C on the accelerator plug by a Red/green wire, both the terminals have blanking pins and no wire.
A combination of the fault codes and gut instinct led us to believe it to be an earth problem. We ran a wire from the body of the ECM to earth and have tested it extensively and so far so good. Will report back in a week, but confidence reigns supreme!