So, here's a bit weird...

Currently have removed old remote receiver due to key fob not working, and having to lock/unlock D2 with key. So yesterday filled up with diesel at garage, left car unlocked, went off to pay and when I tried to start the car nothing happened. No turnover, nothing. All the instrument lights came on ok when I switched the ignition on, but then no joy. Assumed it was immobilized so tried the EKA, with no success. Two kind chaps helped me move the car away from the petrol pumps, and we were just about to try a jump start when I tried the key once more, and this time it started - and has been fine since. Only other thing I noticed was that I had trouble shutting the fuel flap and it would not open again when I tried later. Removed fuse - it was ok - replaced it, and then the fuel flap opened fine. Could that have affected the immobilizer somehow - bad earth somewhere maybe? Could the remote receiver not being in place have had an effect? Or could this just have been a random thing that happened?

I think I mentioned the othe day that the BCU sounds as though it is affected by water.

Most of those functions are BCU-orientated in some way.

Also check the internal fusebox down by your right knee, that is another one that gets corroded terminals on the connectors through water ingress.

Peter


Peter

thank you - will check the BCU - can you just take it out, clean it up and put it back again without messing up any settings?

Also currently dealing with some BCU issues that started about 2 weeks ago. First time it happened, locked car with key fob for the night, tried reopening it the next morning and nothing.... it was as if I was trying to get into someone else's car with my key.
Tried a spare key fob I had received from the previous owner and it still wouldn't open up. I unlocked the vehicle with the key in the lock and the alarm went off. Quickly opened the bonnet and disconnected the battery leads but the alarm kept going for a few more minutes and probably woke up half my neighbourhood in the process
Waited about an hour, reconnected the leads, alarm went off again but this time the key fob had started working and I was able to turn the alarm off and get the car started.
Parked at work, lunch time, tried to get into the car and both keys failed to unlock the car again. I let it stand till close of day and it started responding to the key's signals again.
On the drive back home, the door locks cycled between lock and unlock at random 4 separate times.
Now the problem keeps coming back randomly. Sometimes the keys would work and the doors would unlock with no problems, and at other times it wouldn't respond and I would be left locked out for days (record stands at 2 full days now). Don't really know what I can do now. I'm tempted to leave it unlocked so I don’t have to deal with the drama anymore, but it's obviously not the best idea.
Would be interested to know if there's anything that I can do.

Sounds more like the starter contacts to me which will give you intermittent starting.

The BCU is behind the glove box by memory, and it all unplugs.

Check the contacts on the long edge, but don't go poking at them unless they need cleaning.

The box is a snap together arrangement and you can get inside and look at the board. If it is clean with no signs of obvious corrosion or overheating, that's as far as you can go visually.

The passenger compartment fusebox is behind the cover down by your right knee, it is also a pluggable unit but they do have a history of corrosion on the connector pins caused by water coming from above.

Not dismantleable, not all the relays are unpluggable either.

The worst affected seem to the the connections on the back, have a look at those.

The IDM unit is integral to this box, don't poke at it, just check all is clean.

Because so much of what happens in the car is controlled by these two units, especially the BCU, be careful about how you treat/handle them. If the BCU is faulty it is fairly expensive to replace.

Peter

listerdiesel said:

The passenger compartment fusebox is behind the cover down by your right knee, it is also a pluggable unit but they do have a history of corrosion on the connector pins caused by water coming from above.

Not dismantleable, not all the relays are unpluggable either.

Click to expand...

It is (at least you can take the cover off carefully and clean the tracks etc). Agree about the relays.