Mk2 Focus Electrics going mental after flood yesterday

[tinhead]

Had to drive the car through some serious flooding yesterday to get it MOT'd (which it passed with flying colours)

Car was perfectly ok on the drive there and back but 4 hrs later while sat on the drive it went full on Herbie, thought it was just the alarm at first but as well as the horn/hazards, the headlights were flashing and windscreen wipers were randomly working, could also hear other things switching when I lifted the bonnet, all this with the ignition OFF.

Disconnected the battery and left it overnight but this morning its doing the same (no horn this time thankfully), water ingress would be the obvious suspect and I read somewere that the ECU is behind the bumper in the NS wheel arch which would make sense as that side got the most water but there is nothing but an air intake.
Checked under the glove compartment and the fuse board is perfectly dry as is the relay/fuse board under the bonnet. The only "ECU" I can find is the engine control module ECU mounted next to the battery, is this only for engine control and is there another main ECU somewhere else that could cause these random things to switch on/off?

Car is an 2005 focus 1.6 petrol

Thanks for any help

[normalbloke]

Sell it. Fast.

[GreenV8S]

You may get lucky and find you can get it working again by opening all the electronic components that have water damage, and cleaning them with electrical cleaner. More likely you have destroyed electronics which will be expensive to replace, and got the wiring wet which will lead to corrosion related problems in future. Insurance companies commonly won't even attempt to repair flood damage because it can be so problematical, and will simply write the car off.

Don't drive through flood water next time.

[Krikkit]

Get on eBay and look for the same car of the same age which someone's breaking.

Buy the wiring looms, ECUs, everything you can get hold of.

Strip out the ruined bits, replace with the new items. You'll probably need to replace all the ECUs as they'll be tied together, possibly the clocks as well. Ford-specific forums might be able to tell you.

[GreenV8S]

PS some of those symptoms sound like an upset alarm. But wipers coming on suggests you have more widespread problems.

[Munter]

The OP is asking where things are.

Replacing them once he knows where they are would be the second step.

"is there another main ECU somewhere else that could cause these random things to switch on/off?"

[tinhead]

Munter said:

The OP is asking where things are.

Replacing them once he knows where they are would be the second step.

"is there another main ECU somewhere else that could cause these random things to switch on/off?"

Thanks
That's what I really need to know, nothing ive found so far has shown any signs of water ingress, I want to know is there another component apart from what ive mentioned that could control all these things even with the ignition switched off?

Also, I know I said I drove though a flood but I probably made it sound worse than it was, there was dozens of other people on the same road and I was going slower than most, its not as if it was up to the bonnet or anything.

Edited by tinhead on Wednesday 7th October 16:31

[tinhead]

After a bit more digging it seems I misidentified the fuse/relay module under the glovebox, apparently this is the GEM module which controls many of the electrical devices in the car including the wipers, and is linked to the instrument cluster and other modules through the bus.
I'll disconnect it tomorrow and have a closer look.
It may even be a massive coincidence and nothing at all to do with the rain, like I said I probably painted a worse picture than the reality which was no worse than any modern car should drive through without issues, which it did to be fair.

[stevieturbo]

If you can find which components or wiring got flooded...there might be a slim chance to try them out. Very slim.

But next time have a serious think before you choose to deliberately try and drive through a flood. Just apply a little common sense.

If you wouldn't walk through it....why drive through it ?

[GreenV8S]

tinhead said:

It may even be a massive coincidence and nothing at all to do with the rain

Fingers crossed, but unfortunately the symptoms and timing do suggest water damage as the most likely culprit.

[tinhead]

stevieturbo said:

If you can find which components or wiring got flooded...there might be a slim chance to try them out. Very slim.

But next time have a serious think before you choose to deliberately try and drive through a flood. Just apply a little common sense.

If you wouldn't walk through it....why drive through it ?

Its probably my fault for my description in the first post but nothing in the car has been "flooded", I was just driving along an ordinary road that was struggling to cope with the sudden deluge, and along with many other drivers was driving slowly through the worst bits (mainly near the kerbs)
I don't think it was reckless, and yes I would have walked through it, in fact I did the same journey on my motorbike 1/2 hour earlier so it couldn't have been so bad.

Now ive discovered the GEM module (sometimes called body control module) is more than likely the culprit i'm more confident of a positive result, either by drying it out or if I have to replacing it as they're not very expensive second hand.

[GreenV8S]

tinhead said:

Now ive discovered the GEM module (sometimes called body control module) is more than likely the culprit i'm more confident of a positive result, either by drying it out or if I have to replacing it as they're not very expensive second hand.

That's encouraging. Assuming you manage to dry it out, it's worth cleaning it with non-residual cleaner to remove any surface contamination that could cause a current leak. It's easy to damage electronics so cleaning might not be enough, but if you do need to replace a module there might be more to it than just plugging in the equivalent part number; sometimes these modules are coded to each other, presumably as a security measure.

[stevieturbo]

tinhead said:

Now ive discovered the GEM module (sometimes called body control module) is more than likely the culprit i'm more confident of a positive result, either by drying it out or if I have to replacing it as they're not very expensive second hand.

Modules like that may need coded to the car. And on some cars, divorced from the donor car prior to removal.
Vauxhalls of that age were silly like that.

[tinhead]

Found the problem, when I removed the GEM one of the connectors had been badly affected by moisture and corrosion, its obvious by the severity of the corrosion that its been a long term issue and not just caused by anything that happened 2 days ago, although that probably tipped it over the edge.


Unfortunately it was that bad one of the pins has broken off, but decided to dry it out and clean up both sides of the connector without opening up the module or repairing the broken pin just to see what works.
The good news is all the random switching has stopped and everything in the car is working normally again apart from the remote keyfob.
Ive just tried reprogramming the remote in case it was due to the battery/GEM being disconnected for so long but no luck, so it may be due to the broken pin or other damage to the pcb in the GEM.
I'll just run the car as it is for now, losing the remote locking is not the end of the world (central locking still works), I may pull the GEM apart in the future and run a wire off the pcb to replace the broken pin and see if that fixes the remote.
Also still need to find why there is water getting onto that connector alone, all the others were perfectly clean and dry, just put it back with plenty of silicone grease for now.
But i'm just glad the cars working again, its may be 15yrs old but its just passed the MOT without a single advisory and the only upkeep has been £3 for wiper blade refills in the last 12 months .

[Penelope Stopit]

Suggest you do split the module for a visual check before using the car

[GreenV8S]

That's encouraging.

If you do have water getting in to wires, connectors or electronic modules the damage may not show up for a few months. If you were planning to replace the car in the next year or two, you might want to reconsider the timing of that.

[tinhead]

Penelope Stopit said:

Suggest you do split the module for a visual check before using the car

Like I said i'll probably split it later to finish the job off properly, the main priority this week was to have the car working.
I'm not too stressed about it now I know were the problem is, I've seen a lot worse in my job

As regards selling the car, apart from this issue (which is fixable) the car has been 100% reliable over the last few years and at this price level I could end up with something with worse hidden problems, it may be a case of better the devil you know.

Thanks

[Zener]

That unit is on the BUS and some of the loom exits the firewall/bulkhead I would suggest you check the loom for breach or the loom interior to exterior grommet , another area to identify for that moisture ingress may be a blocked scuttle drain the water comes in through the heater system air intake , like mentioned if you replace this unit it will need coding to your particular car/variant , dry that unit properly paying aprticular atention to those pins and the plug this stuff got me out of similar situations may times , dont use WD40 or similar, good luck

Edited by Zener on Friday 9th October 12:44

[tinhead]

Quick update, car has still been working fine but getting a bit tired of having no remote locking so i removed the GEM module to clean up any damage inside and attempt a repair on the broken pin which i'm fairly certain is causing the problem with the remote.

Unit was easy to split after removing all fuses/relays, tidied up some more corrosion on the pcb around the connector, couldn't get access due to the dual layer board to solder a wire directly onto the rear of the broken pin but luckily I traced it out to one of the "link" pins joining the two boards.
soldered a wire in place of the broken pin and brought it through the case and connected to matching cable in the loom.



Great news, remote locking working again straight away, must have been the broken pin, also the connector is labelled "Roof 1" and I think the remote antenna is up there so that follows.
Also reset the one push window raise which I forgot to do last time after disconnecting the battery.
Have checked for any blocked drains etc as suggested but also noticed some condensation on a cold day on the steel crossmember under the dash, the car is left outside unused for days on end and does feel a bit damp inside sometimes so that could be partly to blame, it was definitely more than just driving through a deep puddle that time.
as well as silicone grease on the connector I've put a sheet of polythene above the module just in case anything does drip from above, I'm confident it'll be fine from now on.
So the people telling me to sell the car/replace the wiring loom can all relax now and take a chill pill, all in a days work of running a cheap car.

Edited by tinhead on Wednesday 11th November 13:59

[Richard-D]

Result! Well done, I like a free fix. The overly dramatic people earlier in the thread could learn a few things from you. They won't, but they could