Intermittent Immobiliser problem

[WillBox]

Hi all, and thanks for any help you might be able to offer to this problem.

I have Peugeot 107 ('06) which I believe has Toyota electrics (same as an Aygo), so I hope its OK to ask here (essentially the same car). A few days ago it wouldn't start, the engine just cranked over. I fully charged the Battery just to rule that out. Had it towed to a garage. They said there was a fault code relating to a comms issue between immo and ecu. The guy said he reached under the dash and 'wiggled' the immobiliser, and the car started again, but wouldn't ten minutes later. He quoted £900 for a new immo installed from Peugeot, or £500 for a breakers yard immo/transponder/keys etc. The first is too expensive, and I don't think I'd trust the second option to last or even work. I was also suspicious of his reluctance to check out the cabling, as it worked when physically manipulated. He insisted it was "probably some loose solder" in the immo box and that it would need to be replaced.

He got it started again by wiggling underneath the dash, and I paid up (tow/diagnostic/time fee) and took it home instead. Strangely, it continued working fine that evening, but stopped again the following morning. I removed the dash to see if I could see anything cabling-wise, but can't get under the immo to remove the cable and check it out. I'm assuming this is where the problem might lie as this is what was wiggled. However, no amount of wiggling is now getting the car started.

Does anyone have any idea of what to do/try here? My assumption is that it isn't anything to do with data sync/mapping etc, but a connection issue. Is it worth checking all the fuses? There was also heavy rainfall the nights prior to it not working. Everything looked fine (i.e dry) under the dash, but is there a vulnerability under the bonnet (specifically behind the engine) that could lead to a immo comms issue?

I would be curious as to whether anyone has experienced similar or knows what to try.

Many thanks

[flash22]

Top of the dash has to come off, as the immo module is at the back of the dash, there is a recent thread on the subject i will have to find it

 

[WillBox]

Hi flash22, thanks so much for your reply (and the thread which sounds similar - lots to learn). One question, I thought the immo box was the one circled here, am I wrong? 

[flash22]

That's the one, a right pain to get at

 

[Stecha]

Will, have you tried your spare key ? its a long shot.but, worth trying

I know one of my keys played up like that, the other didn't

[flash22]

It's rare for a passive chip to fail - on the other hand, these immo modules do fail and don't talk to the ecu correctly

 

It's also worth getting your Battery and alternator checked

[WillBox]

Hi Stecha yes I did try the spare key 😞 I fully charged the Battery also just to rule it out. It does seem to be an ecu comms issue from the garages diagnostic, with the wiggling-then-works episode making me think (hope) its a cabling/connection issue rather than the immo failing. But obviously I could be completely wrong, I don't know too much about this stuff.  

One thing that's bugging me is that there was heavy rainfall the two nights before it stopped working. Is there anything behind the engine or at risk of humidity that I could check? Also, flash22 could you let me know what the other black box is at the back under-dash, sticking up in the photo - if this is connected to the immo is it worth checking the connections there also? 

Thanks for your help guys, I really hope I can somehow sort this.

[flash22]

The ecu lives behind the fuse box, the ecu plugs are watertight if correctly seated, the scuttle may not be draining properly and holding water

pop the wipers off and remove the rubber to release the top of the scuttle and have a good look

 

[flash22]

The upright box iirc is the door control ecu aka remote locking and nothing to do with the immo