AL4 fault diagnosing

[xantom]

Hi, My Xantia Mk2 Auto has an AL4 gearbox which has symptoms the internet tells me a likely to be the valve controlling the Torque Convertor Clutch. I'm jpretty satisfied that's accurate given the sym,ptoms but before getting a new valve I'd like to check the control signal to the existing valve, just in case the problem isn't mechanical. I've got a guide to which pins to check line resistance across but I'm struggling with locating the '33 way grey connector' and the Transmission ECU. Can anyone tell me where these are, please?

[xantia_v6]

The 33GR connector is on the top of the transmission itself I think. The ECU is probably mounted under the battery tray (remove the battery and tray to access it).

Note that if your transmission has not previously had the solenoids replaced, then you MUST have the ECU software updated to work with the improved replacement solenoids.

[xantom]

Thanks Xantia_V6, I'll have a look tomorrow. Should have mentioned I've done the initial step of an oil change, putting 8 new litres through it in 2 go's, so I'm happy the oil is okay. Changing the valve shouldn't be too sccary as the access to it is pretty good on the Xantia. As regards the new/old valve types my money's on it having the original valves so my first hope will be to find someone selling the 'white connector' ones, af anyone still does. Otherwise a garage will be making a little money out of me.
Tom

[DHallworth]

Is it a simple change of settings using Lexia to reflect the new solenoids in the gearbox or is it an actual update that needs to be carried out to the ECU?

[xantom]

David, you beat me to it. Yes, I found the Transmission ECU when I was clearing the way to remove the Hydraulic distributor. I've checked the solenoids and the 2 big ones, oil pressure and Torque converter clutch, are dead. I'veordered new ones but yes, my box had the original white connectors on the 2 big ones. So David's question above is from me too, does anyone know if the update instructions already part of the Lexia software?

[xantom]

Hi, All, this follows on from a post I recently made about sorting out my AL4 Auto box in my Xantia. I've got new oil pressure and torque converter clutch solenoids but my originals were white plastic connectors, these are the newer black ones. I understand I have to let the ECU know of the change as they communicate at a different signal speed. David in Glasgow has kindly offered to do it with his Lexia but neither of us know for certain if this update information can be set in the ECU with the Lexia as it stands. Does anyone out there know if the Lexia software can achieve this update or is this something I'm going to have to pay a citroen dealer to effect for me?

[xantia_v6]

Old updates like that one were originally shipped on the Lexia update disks. In Lexia, there should be a text page with a list of available version upgrades, by car model. If the upgrade you require is listed, then it might work.

[xantom]

Thanks. I'll let David know and he might be able to check if this is on his version.

[DHallworth]

Sorry to bump this again...

Tom needs his ECU sorting after changing the solenoids in his gearbox.

Does anyone know if it's a simple setting that needs changing in the ECU settings to reflect it's now got the Borg Warner solenoids or is it an ECU update that's required to let the ECU know they're fitted?

Thanks,
David.

[GiveMeABreak]

Hi David

If you have fitted the new BorG Warner electrovalves then the ECU needs new software downloading, or there is the risk of destruction of the gearbox.

Citroen state:

Replacement of a hydraulic block or the solenoid valves alone:

ESSENTIAL:

• Observe the safety and cleanliness recommendations.
• After the exchange, download the automatic gearbox ECU using the diagnostic tool equipped with CD 27 or later (follow the diagnostic tool procedure).
• Engrave the 2 letters BW after the identification no. on the rear casing of the automatic gearbox Example (20 TP 94 B W).
• Change the modulation electrovalves in pairs.

So if you have access to CD 27, or it has been installed on the laptop, it should have the relevant software available, otherwise a dealer can do this if you don't have access to that CD. Or if using Diagbox with the encapsulated Lexia software, I would expect that it would already contain the ECU update. The procedure is guided so should do this for you. Make a note of the current software in the gearbox ECU and compare it after attempting the update to see if it was successful.

[DHallworth]

Thanks Marc,

My Lexia software is an early version and as far as I'm aware didn't have any of the additional CD's loaded on.

I do also have a separate laptop running Diagbox Version 07.15.

Quite happy to help Tom out having a look for him but I've never done an ECU update using my kit and don't want him to have to drive through here for no reason before his ECU is updated now he's fitted the solenoids already.

[GiveMeABreak]

I see the predicament David. As you can appreciate, I can’t advise if it would already be on your version of Diagbox, so it may be better for this specific operation to get a dealer to update it for the cost of a diagnostic, unless anyone else can confirm the software update will be included on that version.

[xantom]

Thanks Guys, been following what's been said. I'll call the Citroeb dealer here (That's Stirling for me) and see what they say and what they charge. Probably have to just grin and bear it but it always disappoints when I very rarely have to resort to garage services.

[GiveMeABreak]

Best to drive it for as little as possible until you can get it sorted Tom. Also as you can see, the following procedures need to be done:

The dealer should be aware, but as this is an older gearbox by today's standards, make sure they are aware of the technical info and procedures they need to follow after the ECU download.

The following state what needs to be done and for which operation, but also note the important point about the engine ECU update after the gearbox ECU update!

ECU Downloading
This operation is to be performed in the following cases:

• Updating the gearbox ECU
• Adapting the gearbox ECU to a change in the engine ECU

Downloading must be followed by:

• Initialisation of the pedal
• Configuration
• A road test

ESSENTIAL: The engine ECU must be updated each time the automatic gearbox ECU is updated.

To perform a downloading operation, follow the diagnostic equipment procedure.

Initialising the Throttle Pedal

This operation is to be performed in the following cases:

• Control unit replacement
• Replace the gearbox
• Update by downloading
• Accelerator cable adjustment

To carry out the pedal learning, follow the diagnostic equipment procedure.

Configuration
This operation is to be performed in the following cases:

• Control unit replacement
• Downloading of the control unit

A new or recently updated ECU must always be configured with the following three options:

• "Shift lock" gear lever locking
• Air conditioning
• OBD output (L4 emission standard)

The ECU configuration operation consists of suppressing diagnosis of options which the vehicle does not have.
For configuration follow the diagnostic equipment procedure.

As far as the last procedure goes, 'Configuration', you may need to just check that the options are the same as they were - as this isn't a new ECU.

So it may be worth your while with the dealer visit to get all the above done at the same time.

[xantia_v6]

The Lexia that I use with my Xantia and XM is I think v7.62 and it was installed from CD 42. It offers the AL4 solenoid update, but as my car's don't have that transmission, I don't know if the download works.