Peugeot 407 al4 gearbox problem

[The_gladiator]

My car is Peugeot 407 2005 2.0 L petrol engin with al4 auto gearbox

About 3 month ago I received the oil wear counter warning
So the technician he replaced the whole gearbox oil (I am not sure what type of atf he used) and he reset the oil wear counter.
And from that day my problems starts

I start receiving 2 errors mostly after long drive
P0006 pressure regulation variation/ recommendation
P0070 converter lock-up
And when this errors trigger the gearbox go to 3rd gear and I have PRND and followed by dash on the screen (-).
After restarting the car all back to normal for some time and trigger again.

After that the technician replaced one of solenoid valve
From that day the errors start triggering more frequent
Previously errors only after long run specially when driving in mountains.
Now error appear in case of cold start after 1 km ,and appearing in any roads mountains or straight.

But the error repeating interval was reducing day by day.

Then we suspected that the atf was replaced with bad type and decided to change it last week.
But unfortunately esso lt 71141 or mobile lt 71141 not available in my country.
So the technician replaced the aft with other atf just to confirm if the problem from atf and to see if any improvement.
For first days the error repeating much more than before and slowly reducing day by day
Only
P0006 pressure regulation variation/recommendation. Is showing
P0070 converter lock-up. Not showing any more
Any way after few days driving the error p0006 repeating reduced so much until suddenly it start to appear every few minutes
Yesterday morning another surprise the gear start to slip without any error
I drives about 2 km and the gear slip on about 2000 rpm
Now I am afraid to move the car
I have called the technician and he said he will replace the valve body and may replace the 2 valves as well. And the ATF for sure ( I trying to get esso from abroad).

Please not that I have lexia .

Any help will be appreciated.

[CitroJim]

In these gearboxes only genuine LT71141 ATF must be used and nothing, absolutely nothing else is suitable, not even those that claim to be compatible with LT71141. Simply put, they are not. I do suspect this is the root of your problems and sadly it is possible damage has occurred. It is very much hoped this is not the case.

That the symptoms have changed yet again with a further change of ATF suggests this is the root cause and it is hoped that a change to LT71141 will resolve the issue.

It is essential to obtain genuine LT71141 but do note that to effectively flush out all the existing ATF three changes will be needed as a drain only gets about half out as the other half remains trapped in the torque converter. I do appreciate that given your location obtaining the correct ATF may be very difficult.

Although I have no direct experience of the AL4 there are known problems with the pressure regulation solenoids but with these problems normally develop slowly and not suddenly.

I wish you the very, very best in fining a resolution to this problem.

[The_gladiator]

Thnx Jim for your reply
I was going through the fourms
I found some body experience d same problem and finally he replaced the pump and the filter inside the gearbox and that solve his problem.
My question if I find esso lt 71141 and flushed the old oil
Is that will solve the problem or clear the filter
Or damage happens already?

[CitroJim]

I would do two, ideally three, oil changes first for genuine LT71141 first and see if there is an improvement. If not then is the time to start thinking of an overhaul...

[spider]

I'd agree you need three changes to get it all out as you only really drain 1/3 or 1/2 at most, given a large amount is still in the converter.

I've only had to do a 'full drain' once on a different make and I did the following (it did appear to work however): Drain and refill. Run engine. With footbrake applied move into Drive and open throttle for about 5 seconds (not enough for a 'stall speed' test, just enough to make sure it was really 'trying' to go! 1500rpm is *more* than enough for this, don't take it full throttle or to stall speed test) , repeat in Reverse and then once more in Drive again. Let trans warm up now at idle in Park/Neutral for about 10 minutes. Once its warm, stop and drain. Repeat twice more.

The advantage of this is (1) you do not have to go anywhere (important for me as I may not get a space upon my return!) and (2) apart from the initial 'surge' (I think this is helpful as you're 'loading' the converter a little forcing fluid under more pressure?) its not under any loading so 'wrong fluid' should not cause more damage.

From memory the older (mechanical unit with dipstick as fitted to 405/309/205 etc) HP20 unit had two drain plugs so you could get 'more' out whereas the AL4 just has the combi level/drain plug fitted...

[Stickyfinger]

In Homs ?....WOW....tough place to live, take care

[The_gladiator]

Thank for u all
But I already did 2 bad oil change
And 3 more change
That is coasting almost same second hand gearbox
As the results is not confirmed

What u think ????

[The_gladiator]

Now I test the car for 15 km drive in mountains roads
First on cold
gear slip in reverse
Then on drive it slip one time only on 4th gear
But the error msg p0006 (pressure regulation) it is appearing so much and the gear go to 3rd (refuge)
At the end of the test I tested the reverse and worked OK without any slip
What I observed from lexia during the test

Before the error trigger I have two indication in advance
1 little unexpected change in the rpm
2 on lexia there is changing law
Normally this value is economy or some other value depending on the situation but before the error trigger the changing law always go to unbridged pattern
And the error always trigger on this value

So any advice what this value effecting
The other question what the difference between oil pressure and guided pressure

Thnx guys

[CitroJim]

From the Lexia results it sounds like the old well-known problem of the pressure regulation electrovalves... The are allegedly easy enough to replace and freely available on ebay - a testimony of how much trouble they give...

There's a good few threads on here about them too... Mandrakes post in the topic dealing with an Xsara slipping into Neutral has a few choice ones...

Also in there is a link to an ebay listing for the electrovalves...

[spider]

I *think* its only the 207/208 and *not* the 406/407 that if you change some of the solenoids you *have* to visit the dealer as you need an updated program in the ECU as the solenoids are different. I forget the specifics about this unfortunately. I do not think it applies and I'm not sure how driveable it would be without programming. Unless the Diagbox can be *ahem* convinced to download the relevant update...

[The_gladiator]

I agree with u spider as in diagbox it is written no need to update the ECU for 407 in case of solenoid change
But maybe the last solenoid I replaced is fulty
Maybe

Can u tell me please or any body can advice if I can update the ECU using lexia with diagbox or pp2000 installed (Chinese)

[spider]

I agree with u spider as in diagbox it is written no need to update the ECU for 407 in case of solenoid change
But maybe the last solenoid I replaced is fulty
Maybe

Can u tell me please or any body can advice if I can update the ECU using lexia with diagbox or pp2000 installed (Chinese)

The problem with the update is not "applying" it (that's quite easy!) the problem is getting it.

From memory (it was Diag2000 last time I did an update) you cannot 'get' the update data as it has to come straight from PSA. I think it also is not saved, its downloaded and directly flashed*** into the ECU, so you cannot "keep" a copy. It may be possible to force it to keep a copy without that much difficulty if it does save it complete but then it may not be useable again for another car as (1) it may differ as I bet its exact 'current version' specific and (2) 'diag' would expect to be 'fed' from the download server not a local copy of the file.



*** Not relevant but a useful point ( anyone who knows a bit more can help or correct me please, appreciated ) Unsure on this, from a technical point of view this is *very* unwise to do if there is a communication issue as the ECU could be killed as if its not at least cached in the 'local' hardware prior to being written out, I mean a 'direct link' between PSA and your 'open' ECU. (think of turning your PC off during a Bios update for example!) however it is likely 'patched' in blocks. I'd suggest if its say an 8MB update (ECU's are not big anyway) then the 'update' is applied in blocks of 512KB or so.

[CitroJim]

I would only ever risk updating an ECU if there was a clear and very, very good reason to do it... Else leave well alone..

And yes, Andy, any update carries risks...

[spider]

I would only ever risk updating an ECU if there was a clear and very, very good reason to do it... Else leave well alone..

And yes, Andy, any update carries risks...

Concur.
207 you *have* to if you've changed any of the solenoids as the code is different for them as they are a different make. I've seen it mentioned a few times in various places. What's not clear is if it will remain drivable to the dealer or not (and persuading them to do it I guess, depends on the person you speak to) , I would at a minimum expect even with a more or less total shutdown it to go to 'limp' mode aka 3rd gear only.

[CitroJim]

Yes, even with no electronics at all, 3rd emergency will be available...

The 4HP20 needs to be re-initialised on change of any solenoids/electrovalves. Similar I expect to the 207 work...