AL4 Gearbox home repair questions.

Hi everybody,
I have just registered with the forum after studying various posts and finding it a mine of info.
My wifes 04 Reg C3 1.4 automatic, although only covering 33000 miles has started to display the dreaded snowflake in the display . I following various posters advice purchased the latest Lexia\diagbox 7.55. Connected up and it shows gearbox fault code 06, (pressure Regulation difference/setting ) This seems to show that the pressure control electro valve is probably at fault. Dealer quoted over £550 to rectify !! Nearly half the value of the car.
I have studied various posts and watched very good videos on Youtube on changing these, unfortunately they all see to be Russian, (good job pictures are universal). I even found the new valves part No 257416 on Ebay for £60 a pair. Dealer said about £100 each.
I consider myself a competent DIYer having maintained all my cars for 45 years, from Mini's to Maserati's so intend on giving it a go. I have just a couple of questions for those out there with more knowledge / experience than me, so here goes.
1/ Sometimes mentioned is the use of a special tool M1 for setting internal selector control. Is this necessary as none of the videos show it being used? what is its purpose? is it just to align the selector arm while tightening it back up, if so can I make one from a bolt and washer/spacer before I remove it.
2/ Having fitted the new valves it is mentioned that a software update is recommended. Can I do this with the Lexia\diagbox my self or is it a dealer only job. If I can do it does anyone have knowledge of the procedure they can share.?
3/ I was told by the dealer that because I don't have the two piece drain plug my box is sealed for life and cannot be drained only level checked. But on one of these videos it shows a second tube inside the thread that can be removed with an allen key which drains the box completely. Has any body come across this?
Sorry if this first post is a bit long winded, Thanks for taking the trouble to read, and if you have any help please send it my way. Or if you only want to chip in with your two penny worth feel free.
Thanks in anticipation.
I will let you know how I get on after all the excitement is over.

Welcome to the forum JAGPURR

JAGPURR wrote:2/ Having fitted the new valves it is mentioned that a software update is recommended. Can I do this with the Lexia\diagbox my self or is it a dealer only job. If I can do it does anyone have knowledge of the procedure they can share.?

If the new valves are fitted (new type) then the software has to be updated to account for the different timings in the valves. If you are just replacing like for like, then you won't need to update the software.

Its a dealer type of thing, but you may have the updates software on your lexia discs, and Citroen will even give access to their downloads for a fee (but I don't think it will work with a clone lexia, but never tried it).

JAGPURR wrote:3/ I was told by the dealer that because I don't have the two piece drain plug my box is sealed for life and cannot be drained only level checked. But on one of these videos it shows a second tube inside the thread that can be removed with an allen key which drains the box completely. Has any body come across this?

Yes, there are several photos on the forum.

C3CAR wrote:1/ Sometimes mentioned is the use of a special tool M1 for setting internal selector control. Is this necessary as none of the videos show it being used? what is its purpose? is it just to align the selector arm while tightening it back up, if so can I make one from a bolt and washer/spacer before I remove it.

It doesn't look like much. You have a PM with the file that the image was lifted from

Looks like a video of your job?

Hi,
Thanks for the responses so far. Very helpful, the video guru linked does show the job but a more practical series of 4 videos are here

unfortunately in Russian but very helpful non the less.
The comment regarding replacing like for like posed a interesting question. When did they start fitting the new parts? original part no. 257410 improved part no.257416. Also, is it obvious which part is fitted when changing?
Regards

C3CAR wrote:Also, is it obvious which part is fitted when changing?

I don't know, but the documentation says the new ones are BORG-WARNER, so I would assume the originals ones are not. You may be able to identify them from the manufacturer?

You can find the AL4 under Driving Assistance in Downloading:

and handy tips:

Thanks for that Arfur Dent. The diagbox snaps look very interesting, I assume that I will need to be connected to the internet.
Has any body actually done this and can advise how it went?
I have also found some interesting information here -
https://www.aussiefrogs.com/forum/citro ... ement.html
Mentioning when the change over could have took place. ( 2001ish ) Although I think the C3 didn't appear until then, so if we are having the fault in the C3 it must have been later. The article also mentions how to distinguish old valves from new and the possibility of a third type fitted more recently. Not sure if this clears the water or muddies it even more.
Anyway I have ordered my valves from here -
https://www.ebay.co.uk/itm/191372332830?_
At the earliest opportunity ( once I can get the car off the boss ) I will open the box and see what lies there, I'll let you know how I get on.
Keep it coming, please.
Regards

Hi Again,
I understand about downloading the engine updates , ( in case the engine ECU affects the gearbox ).
Checking the oil wear data, is this just so you can replace the data back to as was, after the ECU update?
If so I'm assuming that I will have to drop all the oil anyway to dismantle so would have to fill with new oil.
If this is the case would I have to reset the indicator back to zero, or will this be done as a result of the update anyway?

Regards

JAGPURR wrote:At the earliest opportunity ( once I can get the car off the boss ) I will open the box and see what lies there, I'll let you know how I get on.

If you can also grab some photos of the procedure, that would be a great addition to the forum

JAGPURR wrote:Checking the oil wear data, is this just so you can replace the data back to as was, after the ECU update?

Yes, that's what it says somewhere I read. Obviously the new flashed auto box ecu update will install default values which won't reflect the wear of your box.

JAGPURR wrote:If so I'm assuming that I will have to drop all the oil anyway to dismantle so would have to fill with new oil.

There is a particular type of oil required, the Mobil ATF LT 71141.

JAGPURR wrote: If this is the case would I have to reset the indicator back to zero, or will this be done as a result of the update anyway?

I don't know. I would think the gearbox ecu would expect the clutches/bands and oil to wear in a particular pattern. So changing the oil mid life may confuse things?

JAGPURR wrote:The diagbox snaps look very interesting, I assume that I will need to be connected to the internet.

No, all the lexia functions in the pictures are just from the laptop and not the internet. I have never used any internet connected feature of lexia.

Hi all,
Well thanks for all your help. Great news , I carried out the procedure at the weekend and luckily discovered that I was changing like for like valves so the software update was not an issue. All went smoothly and surprisingly straight forward. Drove the car for 300 miles with out any further issues.
For future reference by others I have taken 15 pictures and written captions to go with them. Is there an idiots guide to how to post these and what section do they need to go in.
regards

The solution is here Replacement of electrovalves AL4 transmission fault code 6