Different Sensodrive Problem

[Citroen154]

Hi,
I have a 1.6 C3 Sensodrive, which 2 years ago had a gearbox rebuild, new clutch, new clutch actuator, new gearbox actuator and a new gearbox ECU and until yesterday this resulted in 28,000 miles of enjoyable, trouble free motoring.
That was until yesterday, when the gearbox decided to change from AUTO mode to manual on it's own, and the back again. this has now happened several times over the 2 days, but there is no knowing when or why this will happen next.
Pressing the Auto button makes no difference and it will not change to Manual at all using the button.
I went to the Main Agent and ordered a new button/switch, but since then I have removed the switch and the problem persists, so I doubt it is a switch problem.
Gear change is still good and as you would expect when in Auto mode and there is no problem in manual.
There is no snowflake or beeps, anyone got any ideas, is there a relay in this circuit ?

[lexi]

Low battery state does funny things but I would try a Lexia check. A live check while driving and fault occurring might show something.
Wiggle test of connections and Multi meter connected can show faults too. There should be a few multi plugs you can check also.

You must have spent a few shillings on that Box! Seemingly it is the Bosch actuators that fail on these boxes?

[Citroen154]

Thanks for the reply Lexi, looks like a visit to the Main Agents ( No independents in my area).
Not sure what make the actuator is to be honest.
As far as cost, yes a fortune was spent, but a lot of it before I bought it. I only had to shell out for the ECU and a reverse gear selector shaft , as everything else had been done and they couldn't understand why it still wasn't right.

[RichardW]

Eeek!! Don't take it to the dealer....

There may be someone in your area with the Lexia kit: http://www.frenchcarforum.co.uk/forum/v ... 19&t=29178" onclick="window.open(this.href);return false;

Otherwise it can be bought for about the same as the dealer will charge just for hooking it up once - which in this case is almost certainly going to be worthwhile!

[Citroen154]

How much are they to buy ?

[RichardW]

Just under £100.... Lexia 3 I bought one of these, and it works on our '08 C4 Picasso and '07 307. There are cheaper ones, but they are not guaranteed to work with later versions of the software, and the interface can be a bit iffy. Not the easiest bit of software to get installed, but invaluable in tracing this sort of issue!!

[Citroen154]

Do you have to buy the software seperately?

[RichardW]

No, comes with it - or there are download links on here.

[Citroen154]

Thanks Richard.
Just had a look on ebay and I assume the ones to avoid are the ones direct from China ?

[charentejohn]

I have one of these but luckily not the problem. One thought is that a reprogramming with current software may help ?
I remember that older pre 2003 boxes when used in Auto mode would revert to manual if you used the paddles to change gear, maybe it is confused.
I know you didn't do this and the software would be the newer one that no longer does this but.... Maybe it is confused, normally a reprogramming is not the answer but may help ?
You could try calling these people for advice http://www.ecutesting.com/citroen/c2-c3 ... fault.html" onclick="window.open(this.href);return false; I haven't used them but they should know about such problems, the link contains fault codes associated with an ecu fault.
More info here http://www.frenchcarforum.co.uk/forum/v ... 11&t=50125" onclick="window.open(this.href);return false; but I would try asking the ecu guys first, costs nothing, and/or a reset as described ?

[Citroen154]

Just thought I'd let you all know that I have found the problem.
Basically, there were 2 causes working together, firstly, the small rubber mountings/fixings has sheared and the ECU was hanging down.
Secondly, water had entered one of the plugs and corroded 2 of the pins, so when the plug was removed, the pins broke off ( well, at least it aided fault finding ! )

The ECU has been sent off to ECU Testing ( I hadn't seen the reply from charentejohn, so that's a coincidence.

The questions are,
1) Does the ECU have to be mounted so low ( ie., on the gearbox )
2) Should there be a waterproof cover on the ECU, or is there one available ?

Any help on this would be appreciated