An unwelcome ECU connector suprise

red_dwarfers · Unread post by **red_dwarfers** » 28 Aug 2008, 22:18

I was getting the car ready this evening to take the aux belt tensioners out for examination and took the ECU out for easier access. Being nosey as I am I unclipped the large connector on top intent on having a nose at it.

Lo and behold, several contacts have corroded and it looks like a couple others having been doing a bit of sparking

What a shocker that was!

Pictures will be uploaded tomorrow!

jgra1 · Unread post by **jgra1** » 29 Aug 2008, 00:57

8)

awaiting pics....

ACTIVE8 · Unread post by **ACTIVE8** » 29 Aug 2008, 19:18

Yes lets see them please !

red_dwarfers · Unread post by **red_dwarfers** » 29 Aug 2008, 19:25

Heres the pictures at last!

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Virdict anyone?

reblack68 · Unread post by **reblack68** » 29 Aug 2008, 19:50

I would scoosh it with WD40 and plug it in again.

Maybe they are all like that, I'll look at mine tomorrow.

DickieG · Unread post by **DickieG** » 29 Aug 2008, 20:04

Hmm, not good I can see why you're concerned, a good clean up is in order there.

andmcit · Unread post by **andmcit** » 29 Aug 2008, 20:05

Would've said that doesn't look very clever; Citroen didn't design it look
like that!! Closer examination and cleaning combined with regular checks
may be called for!

Andrew

jgra1 · Unread post by **jgra1** » 29 Aug 2008, 20:29

wonder what, if any, adverse effects.... ?

Unread post by **xantia_v6** » 29 Aug 2008, 21:25

Once upon a time I had a job where I had to repair this sort of thing.

My first recommendation would be to go to a scrapyard and get a replacement ECU and connector.

It is particularly important to replace the corroded and burnt contacts in the connector, because they will have lost some of thier spring tension.

You could cut the whole thing off and splice in a replacement, or (my preferred approach) you could just transfer over a few contacts as needed.

It should be possible to just clean up the contacts on the ECU, but the resulting bare copper contacts will corrode again very easily (hence it is better to replace the ECU if economically possible.

If you do keep your ECU, filling the connector with silicon grease should keep out moisture and oxygen which would cause further corrosion. I don't normally recommend silicon grease in healthy connectors, as any contamination of the grease can lead to tracking, and the grease itself can hold any trapped moisture.

MikeT · Unread post by **MikeT** » 29 Aug 2008, 22:06

It looks like two pins (3&4 up from bottom left?) are linked by a soldered plate and that the facing sockets are burnt/melted.

XantiaMan · Unread post by **XantiaMan** » 29 Aug 2008, 22:30

Nutcase · Unread post by **Nutcase** » 30 Aug 2008, 04:18

Not good news!
Found a similar problem on my ecu a couple of years ago, a sort of yellowish gunge around the base of several pins, one of which was almost corroded away. I very carefully cleaned out thegunge and scraped corrosin off the pins (didn't seem to be any in the corresponding plug fortunately) then rinsed several times with wd40. Some suggest not using wd40 for this, and in hindsight i would probably use ACF50 now instead (a corrosion inhibiting dielectric spray from the aircraft industry, mainly available from motorcycle dealers - not cheap but does seem v good stuff).
I looked at the option of cannibalising pins from a secondhand ecu but don't think I would have been able to do it without risking further damage. Was very careful when reinserting plugs to ensure the weakened pin was straight and mated with the plug properly. Touch wood have had no issues since.

Good luck!

lexi · Unread post by **lexi** » 30 Aug 2008, 10:16

Get Servisol contact spray. 3 quid a can......great stuff.

Unread post by **CitroJim** » 30 Aug 2008, 10:45

Did you have any clues to this? K light on? Rough running?

Or was it just a nasty discovery when checking your aux belt tensioner?

red_dwarfers · Unread post by **red_dwarfers** » 30 Aug 2008, 22:18

citrojim wrote:Did you have any clues to this? K light on? Rough running?

Or was it just a nasty discovery when checking your aux belt tensioner?

Funny you should say that Jim, a while back I posted a thread called something like "Engine magegment light woes" where it was decided that it looked like a sensor wearing out so I may have found the proper source of the problem 8)

Phoned up a couple of breakers yards this morning and came up trumps with an identical ECU which was from a V plate turbo d xantia (must have been one of the last xantias to have the 1.9td engine I imagine) I took the connector aswell for a tidy £25. I also plugged that sensor back in and went for a drive and wait for it....no diagnostics light!

It does feel like that the xant runs smoother with more poke, but thats probably just me wanting it to