ECU version compatibility and firmware updates sources

Post by **captainkephart** » 13 Sep 2020, 17:42

Hi All,

A general question. How can you find out if your ECU has a 'firmware update' available for it (as these updates tend to fix all sorts of issues). Where do you get them and can you do the updates yourself? If so how?

Also - if you have an ECU, that you think someone has swapped off another car, how can you find out if it is reaallly compatible?
Is there a compatibility list somewhere? Or is it only in Citroen Parts computers ... ?

OK OK, it won't work, yes haha ...

But it might be an older version that's not quite right for a newer model ... so it works, but throws up odd errors at times (like putting slow memory in a laptop, which will work, just).

Ciao, Captain K

Post by **GiveMeABreak** » 13 Sep 2020, 19:04

You have to remember that ECU updates are not that common. The software installed is generally for a specific injection system (talking here about Engine Management ECUs), and updates are rare. Where needed they are usually to fix a specific issue and are detailed in a technical bulletin not publicly available.

This is something only done for a specific reason so I would look elsewhere for any issues you may have as these cannot easily be applied by Joe Public.

Furthermore some updates may only be relevant for a specific engine or later design using the same ECU and therefore updating an older system may do more harm......

Post by **captainkephart** » 14 Sep 2020, 09:18

Hi Marc,
Thanks, I thought that might be the case.

What about the other part ... if an ECU has been swapped into mine from another similar car.

Could that be causing the problems I have detailed in other posts (that you have already seen) O2 sensors: viewtopic.php?t=66037 and hesitation viewtopic.php?t=64136.

How can I find out if the ECU I have is exactly the correct part?

Thanks again, Captain K

Post by **GiveMeABreak** » 14 Sep 2020, 11:40

I haven't the time to re-read all those other posts right now - but if it is the Engine ECU you are referring to then the PSA part is: 1940TK (still available).
It will be a Bosch and this will be marked on the label of the ECU:

Don't forget that the Engine ECU, BSI and Transponders need to be a matched set - so they won't of been able to of replaced the engine ECU without replacing the rest unless they sent it off to be virginised - but would also need reprogramming by a specialist or a dealer....

Post by **captainkephart** » 14 Sep 2020, 18:34

Hi Marc,
Thanks, very helpful. Didn't realise it had to be the whole set.

The numbers you give don't seem to tie up with what I have ... see photo. Maybe I'm just being dense?
Captain K

PS: sorry, links were for other members to follow if interested - didn't expect you to read them!

Post by **GiveMeABreak** » 14 Sep 2020, 18:54

Ok, so I just double checked and there is some slight confusion if this is your Xsara Picasso VIN ending in 549.

There are several possible injection variants fitted to this engine:
Bosch MP7.2
Bosch EDC15C2
Bosch ME 7.4.5
Bosch ME7.4.4 or ME7.4.6
Magneti Marelli MM6LP or MM6LPB or MM6LPC
SAGEM S2000 or S2000 PM1 or S2000 PM2

So I've removed the EDC15C2 reference in my previous post to avoid confusion.

So looking at the date on the injection ECU, I can see that you have the Bosch ME7.4.5 as listed above - and the year of manufacture (22/09/2007) would correspond to being near your actual vehicle build date of (16/10/2007). So I suspect this is the original and one of several variants they could of used for this TU5JP4 engine.

Post by **captainkephart** » 16 Sep 2020, 13:40

Hi Marc,

TVM for the clarification. At least that's one more loose end sorted out.

On the O2 senseor swap post I got this comment:

Unread post by ksanturion10 » Yesterday, 10:10
So you have putted a Sagem coil pack over a Bosch ECM system - nice

Is that right? I should be fitting only Bosch parts to the engine? Is that because signal tolerances will be matched better than with other makes?

Ciao, Captain K

Post by **GiveMeABreak** » 16 Sep 2020, 18:25

Replacement parts from different manufacturers are common and perfectly fine, so long as they meet the original specification. So for example coil packs (part: 597099) - you can have several manufacturers, but at least if you have the PSA part number, then you can compare it to any branded replacement that quotes the same PSA part number. But with engine and ignition parts, avoid ECP and stick to a decent brand and you should be fine.

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