Thread: Landy Xtreme low gear exceleration problems

<span style="color:blue">hey dude....welcome to aulro.....

bunny hopping you say........
sounds like clutch problems.....do you know if the clutch is in good order....?



where abouts are you...?</span>

Thanks for the welcome Defenderzook.
I am from Tassie.
Maybe my description of the problem was too dramatic, feels like irregular, irrational, jerky, fuel delivery, pretty sure its not the clutch.
Thanks for the suggestion though, please keep thinking.

at a wild guess, sounds like a switch or an ECU problem.
I'm pretty sure the Td5 is supposed to change the drive by wire throttle characteristics when slipping into low range. Basically it's like reducing the leverage on a conventional throttle. The response to a throttle input should be reduced, stopping what you are describing. It sounds like this isn't happening.

<div class='quotetop'>QUOTE</div><div class='quotemain'>I'm pretty sure the Td5 is supposed to change the drive by wire throttle characteristics when slipping into low range. Basically it's like reducing the leverage on a conventional throttle. The response to a throttle input should be reduced,[/b][/quote]

im sure it dose too!
hey zook whats that wire you unplug, something to do with
gear changes???? stops the revs changing or something??
its been raised on here b4.

if it was clutch theorectially you should be able to get it in most gears.
timpot, try it in low range and see what happens, im thinking it might
get to a few more gears, eg 1st and 2nd in hi and 1,2 and 3rd in low??

cheers phil.

A lot of people say to disconnect the sensor wire from the clutch master cylinder. Worth a try. Personally have not noticed any real differenc.

Yes the throttle should change when in low range.

this is what you want ide reckon.
august 03 edition of LROI.

right click and save as, then open in paint ect to see it clearer.

cheers phil.

or this is the extract,
bloody document imaging cant read???



T he Td5 engine on both the Defender and the Discovery is controlled on the drive- by-wire system, whereby a positional sensor on the throttle pedai sends an electron signal to the engine control module (ECM) which, in turn, contrds the engine output according to the driver’s needs.
Spotting signs of trouble
When the 1d5 engine was l introduced, some off-road drivers were disappointed with low-speed perforrrance in low-ratio gears. Earlier 300Tdi-engined vehicles wer mown for smooth control of engine speed and traction during very low-speed manoeuvring, wh the throttle control in 1d5-engined vehicles was comparatively jed-cy and less controllable. The effect could cause traction problems in extreme conditions. A second problem of speed surge and/or stalling arose in high-ratio gears when travelling at low speed. These symptoms were apparent when negotiating slow-speed traffic and off rcad terrain, or when driving away from a standstill — especially when towing heavy loads. These characteristics only manfest them selves under specific cumstances, meaning that many owners are unaware thefr vehicle may have a potential problem — and not all vehicles are affected. So. although Land Rover identified the causes and developed a solution, only those vehicles where a problem was identified may have been mod The remainder that later changed hands and were put to different use by their new owners may well begin to exhibit the problems.
If your Td5 Disco or Defender suffers from these condfthns it can be easily transformed by a Land Rover main agent, or by non-franch specialists with appropdate equipment similar to Land Roverè TestBook. But remember — not all vehicles are necessailly affected. So if yours is perforrnin9 properly there is no need to have any work done.
The prob’ems have been designed cut of all later and current models. Jerky throttle control during low-speed manoeuvres This condition was first noticed on the very earliest Td5 vehicles and may also affect Series II Discovesys with VIN numbers 2A 736340 to 3A 782113; and Defenders with numbers 2A 622424 to 2A 642855.
The ECM controls engine performance and operation according to load and running conditions, performance requirements a emissions levels. To control emission output, a small delay in engine response was necessary
after backing off the throttle. In some cases, this delay was a maximum of six tenths of a second but, by revisim t software of the ECM, this has now been reduced to three tenths of a second — giving seamless contrd from the driver viewpoint.
Pre-2002 vehicles used an ECM that cant be updated the problem is eliminated by fitting a later-type ECM that will have the current upgrades and also be further reprogrwnmable. Vehicles of 2002 model year onwards and within the VIN range detailed above have a flash-programmable ECM, allowing a software update to be downloaded from the Land Rover TestBook computer.
Speed surge or stalling at low engine speed
This condition may affect Discoverys up to VIN number YA 250642 and Defenders up to 1 A 605775. Again, the causes are rooted in the ECM — in particular the software corifrolling throttle pedal progression characte and the effect of the idle governor control when ddv off from a standstill or at low engine and/or vehicle speeds. These symptoms will only be rectified after checking that all other engine parameters are in order and confirming the existence of the condition by a test drive.
The problem is rectified by replacing the ECM with the latest version — a job that must be carded out by a technidan with the equipment to transfer fuel injector codes and select various par in the new unit.
Aftermarket-chipped vehicles
Land Rover has not approved any aftermarket chips or remapping modifications to its engine control modules, and does not officially support systems affected by such changes. Once the ECM has been chipped by an aftermarket supplier, the new data will be protected so that it cannot be inadvertantly overwritten by a routine Land Rover TestBook connection: otherwise, reprogramming could wipe out the performance benefits of the chip. Owners of chipped vehicles with the above symptoms must contact the specialist who pro the modification if they wish to have interpretations of Land Rover updates installed. However, aftermarket chips usually include their own versions of any known and necessary updates, so the potential for throttle problems may have been eliminated on chipped vehicles.
HOW MUCH?
The later flash-pcogrammabte ECM is slightly cheaper than the earlier type and can be reprogrammed later with any future updates as they become available. Expect to pay around £352 for the replacement ECM, plus labour costs. The work can only be carried out using specialist equipment to programme the new ECM to your vehicle
A software up downloaded to your existing ECM, is a relatively quick and routine job. Some affected vehicles will, of course, still be under warranty. If not, it may be worth hav a chat with your dealer