p1844 transmission transfer case differential lock-up feedback switch short circuit t

Hi I have a 53 plate td4 auto freelander, with gearbox faults.

It will drive normally for a while (days even a week) but less and less each time, then I will get a harsh gear change with a thump, and the eml, tc, abs, and hill decent lights come up, my revs and speedo stop working and my temp will read max, also the display that usually reads "D" or the gear, will flash between "F" and "4". The car will then be stuck in 4th.

Ive read the fault code logged and its P1844

Im told that is is p1844 transmission transfer case differential lock-up feedback switch short circuit to battery.

What on earth does that mean in english amd how do I fix it??

Many thanks in advance guys

Here is p1844. Look at this picture. At this point I would test the solenoids to see if they all test well. That is the first step.

You have 9 solenoids in the auto gearbox. 'Hippo' has posted a video on utube showing how to check the continuity.
If you search on this forum for jatco auto problems you should find the link.

Try this one
http://www.landyzone.co.uk/lz/f9/jatco-auto-gearbox-problem-223565.html

Thank you for your help guys, I shall track down my multi meter and have a go at this, I shall report back....

I once ran the car through some water, with the underside covers off.

I got the F4 fault and the gearbox stuck in 3rd or 4th.

It turns out that of you get the two bi round connector wet you get the F4 thing.

Also, hippos post state that the connector can become damaged and need to have a cable tie around them to hold them together.

It would be wise to examine them and check they are connected properly, and not getting a soaking from some where.

The connectors are large rounds ones, there are 2 on mine, on the front of the box.

Hi guys, thanks for the advise, after checking the suggested connectors etc I could find no fault, still getting the problem though and less and less miles between each time it threw its toys out the pram, I gave in and took it to a garage, after getting reccomended from garage to garage I ended up at harris mayes in harefield, who took it on, there computer was showing a list of 'can bus' errors ranging from not beeing able to talk to the instument cluster to the throttle angle position and a few other things, the can bus is an information highway running round the whole car talking to everything from the wheel speed to the rear window position, they tested everything thats connected to it individualy and again, found no faults, so in lame mans terms they sent the controll center box thing from behind the dash off for testing as they belive this to be at fault as its job is to take in all the info and re distribute it out to every system that needs it, and all the info apeared to be getting to it, just not out the other side if you like, I understand this is not the ecu or gearbox controll unit its one of the components that tells that whats going on? Anyway, thats where im at, thats been sent away to see if its at fault... if its not im looking at a broken wire in the loom that could be near impossible to find, again I will update as I know more, if this box is at fault my bill will be £520, £286+vat of that is this box thing...

The can bus is the connection between all computers allowing the computers to pass information to each other. Items like the abs sensors are monitored by the abs computer and don't directly talk to the can bus. It's the abs computer that passes the info on the can bus.

Hippo said:

The can bus is the connection between all computers allowing the computers to pass information to each other. Items like the abs sensors are monitored by the abs computer and don't directly talk to the can bus. It's the abs computer that passes the info on the can bus.

Click to expand...

That sounds familiar, well that's the bit that is hopefully the cause and is away for testing, fingers crossed I get to the bottom of this, been without the car for over a week now but harris mayes have lent me an older freelander to use whilst they have mine so at least I can get to work!

Vertuas said:

I once ran the car through some water, with the underside covers off.

I got the F4 fault and the gearbox stuck in 3rd or 4th.

It turns out that of you get the two bi round connector wet you get the F4 thing..

Click to expand...

I learned from the garage the the F4 thing is not actually a gearbox fault its what the gearbox does to protect itself when it loses signal, in 4th its safe as it dosent know road speed or anything 4th is a gear it selects as this will be ok for any speed range....

Not sure what part you've had sent away but the CAN doesn't have anything to do with the CCU on a freelander 1

The CAN network is between the instrument pack, abs, engine and gearbox ecu only.

You need a list of all fault codes from those modules to work out which ones got a fault stored causing the faults to be set in the others

F4 is the limp mode. You can drive it in limp mode but it's very slow to pull away and struggles until up to speed. Best option is to pull over and call out yer breakdown cover. You never know what damage is already done or what could be made worse.