Citroen Automatic Gearbox fault

[Hell Razor5543]

It is possible that a member reading this (and is near to you) may PM you with an offer of assistance. I would, but I am not as knowledgeable with a Lexia as others (although I do have one), plus I am quite distant from you.

[tomthered]

Thanks for that HellRazor hopefully someone can help but any advice and assistance will be much appreciated.

[myglaren]

Have tried messaging several members for help with the Lexia diagnosis but it keeps saying the member is no longer available, despite them having posted in October 2014!! I have tried Handyman as I have been trying to get hold of his brother, cook in fat, in St helens near to us. I have also tried Robert12 and chlorate but no joy with any. Can anyone suggest how to get hold of them please?

Have sent a PM to handyman to test the system and will get back to you on any faults found.

[tomthered]

Many thanks

[CitroJim]

The PM system is working fine...

[tomthered]

have manage to get in touch with two kind members and one who lives not far has offered to run a Lexia Diagnostic on it next week. I will report back as soon as I know.

[CitroJim]

That's good Tom, looking forward to the results...

[KP]

Hopefully this can shed some light on the issue for those in the know

All faults have been cleared so will be watching to see if they come back up.

Also the Fuel Filler sensor has failed, is this the same kind of job as it is on the C5 and just requires the arch liner removing?

The other fault I picked up on was the Aerial or Antenna was throwing up a perm fault but the radio was still fine, Im guessing this is more for the booster circuit than the actual unit itself?

[addo]

Hmm! I'd be checking the grounds including transmission ECU.

[tomthered]

A big thanks to Will for his time and expertise.

@Addo what does "checking the grounds including transmission ECU" mean? Are you referring to electrical faults?

[Mandrake]

With that massive array of faults (no way are all of those things genuinely faulty at once) I would also be carefully inspecting and cleaning the connectors on both the Gearbox ECU and the Gearbox itself with proper electrical contact cleaner.

One green/corroded earth pin on one of those two connectors could potentially cause all those problems...

[tomthered]

so just get under the car and clean any connectors we can find. Never worked on these but is the ECU like a square box and where is it situated and Is it easy to get at?

cheers

[Mandrake]

Not sure where it will be located on a C8. Gearbox ECU's can be in some pretty strange places - in a Xantia it's under the battery tray!

If you haven't already, sign up for a free account on service.citroen.com and look up your car by VIN - if you look up the ECU it should at least have a diagram showing roughly where it is. On an automatic gearbox there is often a large round multi-pin connector. The gear selector switch is usually located where the gear change bowden cable connects to the gearbox, and that may have it's own separate connector, so there could be a 3rd connector.

[RichardW]

It looks like it might be mounted on the end of the gearbox. With that many faults, I wouldn't be all that surprised if it turned out not to be there at all

[CitroJim]

With that many faults, I wouldn't be all that surprised if it turned out not to be there at all

Or full of water...

I know the VW Caddy van has its engine ECU under the windscreen scuttle panel where it gets a bit moist after a while and throws some amazingly random faults as a result.

Many are saved by cracking them open, brushing out all the white corrosion, washing them in IPA and then carefully drying them out...

If the ECU is indeed on the end of the gearbox it may well be rather exposed to the elements. The connector may also be nicely corroded...

Disconnect the battery before disconnecting an ECU!