Unusual trans failsafe question

Hi All,

My cars started coming up with a TRANS FAILSAFE PROG from time to time. Now what I find interesting about this is other than the car driving along as if it's slipping the clutch all the time (tq converter disabled?) it drives normally - goes up and down through the gears fine, and if I knock it across into manual mode I can go up and down through the gears without problem.

For the sake of completeness the car has had a strange issue since I got it - When I knock it across into manual mode instead of telling me I've gone into 'sport' mode, it lights up the 'Low' mountain. When I then go to change a gear instead of telling me I'm in manual mode it just shows the number of the gear I'm in, along with the low range mountain. Additionally when I put the car into low range it doesn't ask me to select neutral, it just waits until I've done so, and then the Low range mountain doesn't flash but you can hear the motor do something and when you drive off its quite clearly in low range, made obvious by the revs!!

Is it at all possible that these faults are related? I've read some things about the potentiometer on the transfer box motor... Could this be at fault? Or perhaps some kind of transmission ECU? I can't find anything quite like it having scoured the internet so I'm at a loss as to where to begin fault finding!!

From a gearbox point of view, its the only one I've driven so can't compare it to anything other than the L405 which i'm sure is completely different by design, but I think to me the gear changes feel ok. Perhaps a little clunky when cold but I've read that this is normal. Also possibly a tiny delay going from D to R and back again, but again I'd say this is only when cold, and doesn't clunk or anything just a small delay, half a second or so?

I had the car scanned today just after the TRANS FAILSAFE PROG came up, as I was on my way to my friends workshop anyway, and it said 'Mechanical Torque Converter Monitor Fault'

Not sure what this means and not sure I like the sound of it either Sad

Hope someone can help!
Cheers
Matt

You need to add some info as to year and model as the diesel and petrol have different transmissions.
Do you have the Rave manual as this explains in great detail what the different components do and where they are located including the ECUs for the transmission and transfer box.

It does sound electronic rather than mechanical failure, what diagnostics did you use ?

Possible info below

http://www.landyzone.co.uk/lz/f10/code-reader-215675.html

Apologies - its a 2003 Vogue TD6. 145k mileage, don't have any record of the gearbox being done but everybody I spoke to suggested theres not much chance of it lasting 140k so is bound to have been done at some point.

Used a Snap On code reader, not sure of the model but I was assured it could do anything and everything as it has regular snap on updates or something...

I do have a RAVE manual yes, will have a read.

I have bumped this one for you as i was guilty of not giving you much help in the hope that Saint or one of the others with more knowledge of the transmission can help you......

I have to say the symptom you describe of the gearbox slipping and Trans Failsafe Prog showing does indicate a bit of an issue with your box.

When the TFP message illuminates the box defaults to (I think) usually 4th gear, and then the TQ starts to slip to prevent the engine stalling...a bit like a manual car when trying to pull away in too high a gear.

The fault message that has come up, would suggest the TQ lock up clutch can no longer maintain a decent engine speed/Gearbox speed ratio as the TQ keeps slipping. I think it is time to drain some oil from the box and see what condition it is in. Odds on it is pretty poor!

The GM5 box on the diesels will eat itself, it if not a case of 'if' but 'when' and after 140k miles I think it is on its last legs....some have gone up to 150k miles before issues arise, and some have gone as low as 40k miles.....it is a gamble whatever.....yours may have been looked after, never towed and done nice motorway pootles all its life so the box has never been 'stressed' but it is now at a stage it is giving up!

Drain the fluid and checking the filter will give an indication on if the box is on its last legs.

Now, I apologise if this is teaching you to suck eggs, so bear with me........

On the L322, to select low range you first have to put the main box in neutral, flick the range switch, it will flash the Lo 'Mountain' signal at you....it will then say Low Range on the dash and the Mountain signal will then remain lit.

Select Drive or move the lever to the left for Manual gear selection and off you tootle....

To change back, slow down to below 25mph (I think, could be 30mph) select Neutral on main box and flick the switch again....mountain flashes, then High Range message, Mountain Lamp out and then select Drive etc and off you go!

If you try to change ratio with the main box in a drive gear, it will ask you to select neutral on the dash display, once you select neutral, it will then commence the ratio change....

Yours seems to indicate a ratio change when you move from Standard Drive to Sport....(lever moved to the left)....and then when you move the lever forwards or backwards it doesn't indicate manual mode but the gear number changes as if you were.....

In Low Range, when you move the lever to the left, it won't say Sport and (now I will have to check mine), but I think it won't say Manual Mode either, as you are in Low Range and you only have two options....normal adaptive drive or manual....there is no Sport option so maybe it doesn't tell you this, but I will have to check mine later this evening on my way home and let you know!

Anyhoo, it still shouldn't change ratio when you move the lever to the left, I can only think there is a short in the wiring under the gear selector surround, and when it gets moved to the left, it shorts on the range selection wire and as such, it then changes ratio.....I'd be inclined to remove the gear surround and check the condition of the wiring, the multiplug connections (they may be damp, and there is arcing/tracking going on) and the like!! They would be my first checks.

Cheers Ant, my guilty feeling has lifted

Thanks Saint for the detailed reply. The thing I find most bizarre is that when i get the TFP message it doesn't lock into 4th, it changes gear normally in both drive and what should be called manual mode although it doesn't say so!!!

When i move into manual mode it shows the mountain but doesn't actually go into low, that only happens when i flick the switch to do so, although the flashing mountain thing doesn't happen, the only indication is the faint hum of the transfer box motor and the fact the revs are suddenly so different for the road speed. Also if in drive and I flick the range selector it doesn't ask me to put into neutral, just does nothing.

It's a difficult one to describe and as no-one else seems to have heard of it or experienced it something always seems to get lost in translation so to speak!!

I'll have a check of the wiring just to make sure.

Another thing, probably unrelated - If I flick HDC switch I don't get any messages or lights to let me know I've engaged HDC, and I also don't have any HDC inactive messages at any point. It seems to work in that when I come off the throttle downhill it slows me down, but then I can't seem to get it to deactivate - It seems I have to turn the car off and leave it for a couple of hours before it'll drive normally again! Not sure if related, just thought id mention it as its all around the gear lever area i suppose!!

The only issue I had around the gear lever area was my low range and HDC didn't work at all when I operated the switch and what mine turned out to be was at some stage the ash try / cup holder situated right behind the gear lever / switch panel had obviously had a a large mocha chocka frappa whatever in it and somebody had braked and shot the lot down inside the switch panel for the low range / HDC.

When we removed the switch panel, which is very easy to do, the printed circuit board on the back was covered in a sticky mess.

We cleaned it all off with my girlfriends toothbrush, don't worry she was out at the time, and some electrical contact cleaner and it has worked perfectly ever since.
As I said, Saint is the expert on this one, but water ingress and the like can cause all sorts of odd things on these cars so may be worth a check at some stage.

I have had the same message on my Sept 2006 Vogue Diesel, which is now on its second gearbox. The vehicle has done 235000 miles, had a hard life cruising at high speed on motorways, towing trailers grossing 3.5 tonnes and a lot of off road work. The original gearbox failed at 165000 miles by just failing to work at all. The current reconditioned one I thought might be good for another 100000 miles however it will go into failsafe mode message normally but not always! when first time accelerating from the house when it's changing between third & fourth if you don';t keep your revs well up. Now the cure, I pull in at the next opportunity, turn engine off and remove key, lock the car whilst still in it and wait for the message screen to go blank. Unlock car, place key in ignition and start engine. Fault then goes away not to be seen most times for the rest of the day even if on long journey. Makes we wonder whether it's an electronic fault, anyway my friendly Land Rover specialist suggests draining the gearbox & changing the filter when it goes in for a service in a couple of weeks as there appears to be no recommended time to change this other than when they break!

chrisrail said:

I have had the same message on my Sept 2006 Vogue Diesel, which is now on its second gearbox. The vehicle has done 235000 miles, had a hard life cruising at high speed on motorways, towing trailers grossing 3.5 tonnes and a lot of off road work. The original gearbox failed at 165000 miles by just failing to work at all. The current reconditioned one I thought might be good for another 100000 miles however it will go into failsafe mode message normally but not always! when first time accelerating from the house when it's changing between third & fourth if you don';t keep your revs well up. Now the cure, I pull in at the next opportunity, turn engine off and remove key, lock the car whilst still in it and wait for the message screen to go blank. Unlock car, place key in ignition and start engine. Fault then goes away not to be seen most times for the rest of the day even if on long journey. Makes we wonder whether it's an electronic fault, anyway my friendly Land Rover specialist suggests draining the gearbox & changing the filter when it goes in for a service in a couple of weeks as there appears to be no recommended time to change this other than when they break!

Click to expand...

Low battery voltage maybe.