salesman talk or not??

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garyfitz123
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salesman talk or not??

Post by garyfitz123 »

Following on from my topic about the 4hp20 gearbox, one of the gearbox specialist who I rang said that as part of their service they would update the software on the car to the latest versions....is there updates available to the ECU softwares? of was it just salesman bullshit? Its for a 2003 C5 2.2 HDi Auto
2003 Citroen C5 estate 2.2 HDi Automatic
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Mandrake
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Re: salesman talk or not??

Post by Mandrake »

There are software updates for some of the ECU's including the gearbox ECU, however they're generally very minor bug fixes or intended to address very specific issues. Anyone with a Lexia can update the ECU firmwares however it is a potentially risky operation as a failed update could potentially brick the ECU.

There is an update for the 4HP20 ECU however as far as I'm aware all it does is adds the very annoying "hold 1st gear to 3300rpm for the first two minutes after a cold start" anti-pollution code, which is intended to warm the cat up quicker but just makes you look like a numpty as you drive through slow residential streets early in the morning at 3000 rpm in first gear :roll:

I updated mine last year and that's the only change I noticed, (and is listed in the update notes) and I wish I could revert it back... :? (Downgrade is not possible, at least not with a Lexia) Unless you're affected by a specific known problem that a firmware update addresses my advice would be leave well enough alone, unless the "gearbox specialist" is willing to foot the cost of a new ECU if it accidentally bricks during the update process, as they are not cheap to replace.

Chances are being a 2003 your gearbox may already have the most recent firmware anyway. Of all the ECU's on my 1998 Xantia, the gearbox was the only one that was not already running the latest firmware. Whether that's because it had been updated at some point in the past or there just haven't been any other updates I don't know.
Last edited by Mandrake on 13 Aug 2013, 19:20, edited 1 time in total.
Simon

1997 Xantia S1 3.0 V6 Auto Exclusive in Silex Grey
2016 Nissan Leaf Tekna 30kWh in White

2011 Peugeot Ion Full Electric in Silver
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1978 CX 2400
1997 Xantia S1 2.0i Auto VSX
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garyfitz123
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Re: salesman talk or not??

Post by garyfitz123 »

okay...i'm putting a 2nd hand gearbox into my C5 rather than getting my old one re-conditioned (£1800 vs £400) and I was wondering was I missing anything by not getting the updates done...probably not by the sounds of it!!
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Mandrake
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Re: salesman talk or not??

Post by Mandrake »

On a 4HP20 you're not missing anything if you don't update the ECU, no.

One thing to be aware of if you fit a second hand box is that the ECU is mounted elsewhere in the engine bay (not sure where in the C5) rather than on the gearbox, so when you swap the gearbox you'll still be using your original ECU which will have "adapted" to the characteristics of your gearbox.

So after fitting the new box you'll need to connect a Lexia and perform an "auto adaptive reset" on the ECU. Anyone with a Lexia can do this, its dead easy and only takes only a couple of minutes, once reset the ECU will "learn" the characteristics of the gearbox (clutch wear characteristics etc) from scratch over a period of half an hour or so.

If you don't do this you'll probably get harsh changes or clutch slip, at least for a while. In theory it would eventually adapt without the reset but it could take hundreds of miles of driving with poor gear changes to do so.
Simon

1997 Xantia S1 3.0 V6 Auto Exclusive in Silex Grey
2016 Nissan Leaf Tekna 30kWh in White

2011 Peugeot Ion Full Electric in Silver
1977 G Special 1129cc LHD
1978 CX 2400
1997 Xantia S1 2.0i Auto VSX
1998 Xantia S2 3.0 V6 Auto Exclusive
garyfitz123
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Re: salesman talk or not??

Post by garyfitz123 »

Thanks mandrake....that makes sense..yea i didnt get the gearbox ECU. I'm thinking of getting a lexia kit myself. If not, there is a very good garage in the town which specalises in the electrical systems...I know they have the proper lexia software so will get them to do it.
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Ben82
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Re: salesman talk or not??

Post by Ben82 »

Gearbox Ecu on the c5 is under the "electronics" plastic cover behind the battery, can't miss the Ecu when the cover is off as it says 4hp20 on it :)
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