AL4 software update

This is the place for all your Diagnostic related questions or advice.

Moderator: RichardW

User avatar
Mr Micawber
Posts: 37
Joined: 03 Dec 2011, 18:45
x 5

Re: AL4 software update

Post by Mr Micawber »

GiveMeABreak wrote:
15 Nov 2021, 11:00
If you can provide your VIN, I'll check the build date.
Thanks Marc. In my 12th November reply to member Wheeler I gave the AL4 ECU data. This seems to say that there has been only one download on 6th June 2003 which is when the car was built.

The car is still with the main dealer, awaiting a response from Citroen UK. The dealer rang me on Saturday morning but didn't leave a message. The service advisor dealing with it doesn't work on Mondays. So far this morning I've tried twice but no-one is picking up the phone. I'm reminded why I started doing my own repairs and servicing all those years ago! :evil:

Simon
wheeler
Posts: 5401
Joined: 21 Sep 2002, 19:07
x 340

Re: AL4 software update

Post by wheeler »

xantia_v6 wrote:
12 Nov 2021, 20:35
Wheeler (drifting slightly off topic), Do you happen to know the version number or disk number of the Xantia 4HP20 update which disabled the "hold 1st gear until 30MPH while cold" feature. I have heard from reliable sources that the update existed on a Lexia CD. I believe it was only installed at customer request, but of course no customer knew of its existence.
OK so the update does indeed exist & the description is 'Changing from 1st to 2nd at 3000 RPM when cold'
For the 4HP20 box fitted to the ES9J4 (XFZ)
The software identification is:
Supp: 007
Sys: 086
App: 003
Ver: 008
Version: 0401
User avatar
xantia_v6
Forum Admin Team
Posts: 7964
Joined: 09 Nov 2005, 23:03
x 520

Re: AL4 software update

Post by xantia_v6 »

wheeler wrote:
16 Nov 2021, 20:01
xantia_v6 wrote:
12 Nov 2021, 20:35
Wheeler (drifting slightly off topic), Do you happen to know the version number or disk number of the Xantia 4HP20 update which disabled the "hold 1st gear until 30MPH while cold" feature. I have heard from reliable sources that the update existed on a Lexia CD. I believe it was only installed at customer request, but of course no customer knew of its existence.
OK so the update does indeed exist & the description is 'Changing from 1st to 2nd at 3000 RPM when cold'
For the 4HP20 box fitted to the ES9J4 (XFZ)
The software identification is:
Supp: 007
Sys: 086
App: 003
Ver: 008
Version: 0401
Thanks for the information. I am not sure if I have a disk with that upgrade, but it will be a few months before I can check. I
User avatar
Mr Micawber
Posts: 37
Joined: 03 Dec 2011, 18:45
x 5

Re: AL4 software update

Post by Mr Micawber »

GiveMeABreak wrote:
12 Nov 2021, 15:28
So what you have written above indicates the same version to me as the update you are trying to apply and why I originally mentioned that the software may already have been updated. If you car was serviced by Citroen, it's possible they may have already updated it - this is normal practice when they service the cars to check whether there are any updates to apply.
Update

I collected the car from the dealer yesterday. They did contact Citroen UK who supplied them with the exact list of specific software which I had seen on my Lexia. As you have said, the various reference numbers given for the Borg Warner electrovalve software are exactly what I have installed.

So it seems that I have probably wasted time and money replacing the original electrovalves because I still have the original fault code and no others. I originally had one saying "sensor power supply" and I found that the fluid pressure sensor wiring insulation had been stripped by rubbing against the corner of the gearbox casing. The three now bare conductors were short circuiting to each other. I repaired that and the fault code did not reappear but it made no difference to the gearbox entering emergency mode. I do have a new replacement pressure sensor so I will try that.

Thanks to Marc and Wheeler for your help.

Simon
User avatar
GiveMeABreak
Forum Admin Team
Posts: 26624
Joined: 15 Sep 2015, 19:38
x 3113

Re: AL4 software update

Post by GiveMeABreak »

Best of luck with it Simon.
User avatar
Mr Micawber
Posts: 37
Joined: 03 Dec 2011, 18:45
x 5

Re: AL4 software update

Post by Mr Micawber »

Original problem resolved

This may help others.

Symptoms
Automatic gearbox enters emergency mode (3rd gear only). Stopping and restarting the engine restores normality but temporarily. At worst this could be for 150 yards of driving or at best for several months of trouble free motoring.

Diagnosis
Lexia gave two fault codes:
03 Sensor power supply
06 Pressure regulation (difference/setting)

Analysis
The wiring loom from the fluid pressure sensor (screwed to the underside of the gearbox) had been rubbing on the corner of the casing over 15 years resulting in destruction of the protective tubing and wiring insulation, leaving the conductors bare and touching each other! All loom clips were present and intact.

Repair
I inserted new wiring, suitably protected and routed to avoid a recurrence. The code 03 "Sensor power supply" did not reappear but the fault remained as did code 06 "Pressure regulation (difference/setting)".

Research
The exact symptoms I was experiencing were documented on the internet. It was stated that the cause is two electrovalves in the gearbox which, during production, were changed from Acutex to Borg Warner. This suggested a reliability issue and was confirmed by Citroën's own technical documentation which also stressed that a gearbox ECU software update is "imperative".

Second repair
I fitted the Borg Warner electrovalves, changed the transmission fluid and set its level at the correct temperature, reset the "oil wear counter" and, to my dismay, the fault remained. I booked the car into a Citroën main dealer for the software update. With the help of the good folk on this forum it emerged that my car had already been updated as long ago as 2005 when the car was under warranty. According to Citroën's technical documentation this should not have been done since the Borg Warner electrovalves were not fitted at that time. :roll: I returned home from the main dealer still driving in emergency mode.

Contemplation
At times like this I often find it beneficial to reconsider the basics. At the outset, in addition to reading the fault codes, I also monitored the gearbox's live data as I was driving. I was interested in two categories: "Selected pressure" and "Pressure". The former gave a varying value and the latter read "0 bar" until the engine reached normal coolant temperature at which stage a reading would appear. I was suspicious of this but the detailed technical data was unavailable to reach an informed understanding. My electronics background also drew my attention to the pressure sensor which had three wires indicating that it was probably an active device rather than a two wire passive one. An old colleague agreed that there was a chance that the short circuiting wires had destroyed the miniature electronics which we believed were contained within the sensor body. This theory was reinforced by Citroën's price for this sensor: £190 plus vat!

Third repair
I obtained a sensor for about £40 and fitted it. The result was immediate; correct, smooth operation of the gearbox with no emergency mode.

Conclusion
If you have the symptoms I had, which seem not to be unusual considering the information available on websites, be cautious about rushing to fit the Borg Warner electrovalves (about £100 for the pair from JP Automatic Transmissions). You just might have a faulty pressure sensor.

Simon
User avatar
GiveMeABreak
Forum Admin Team
Posts: 26624
Joined: 15 Sep 2015, 19:38
x 3113

Re: AL4 software update

Post by GiveMeABreak »

Thanks for the update - a very methodical account that will surely help others.