Hello all,

 

I bought a 2006 1.6l Ford Focus Estate (pictured at the bottom of this thread). Only had it a few weeks before all the below issues occured at the very same time. As they all occured at the same time, it is clear to me that a common fault caused it. I did find a solution that disconnecting the negative terminal of the battery fixed the issue but 4 weeks later  (and 800miles) after the intitial issue the issue returned in the exact same way as described below. 

 

I first noticed anything was wrong with the car when I went to open it one morning and the central locking on the remote didn't work. I assumed the key remote had a bad battery. I used the key to gain entry (where all the doors tend to open due to central locking, but only the drivers side opened). At this point, having not used the remote to open the car, a buzzer should sound as a warning before the alarm goes off. However, this did not occur. The same buzzer should sound when the lights are left on in the car, but this also did not occur. I then discovered that far more was not working:

 

• Central locking not functional
• Warning buzzer/chime does not sound
• Indicators not functional
• Hazards not functional
• Handbrake light remains on when handbrake is released
• Cabin blower motors not functional (ac light does come on tho when it is turned on, just no fan spin)
• Heated front and rear windscreens don't work
• High beams not functional
• Intermittent wipers not functional. Other wiper speeds were functional, but when turned off, they did not return to down position
• Dipped headlights are on even though they are turned off at the switch only (with the engine running)
•  Exteririor temperature sensor reading can't be detected
• Can't open any of the door locks from inside the car

 

Although no engine light was on, I did a code read and one code was detected relating to the position of the throttle body not being able to be communicated with the ECU.

 

I've heard some people say it is likely an ECU fault. I've also read that rather than an ECU fault, it could be the wires connected to the ECU having some kind of fault leading to communication issues.

Apart from these issues, the car seems to run and drive supberb (even before carrying out the "fix").

 

Anyone got any advice on how to track down the actual culpret. I only bought the car for £1000 so paying a garage to diagnose it would probably cost half that plus more on top for the actual repair. Technically I did buy it off a trader, but he's ignoring my messages so imagine he knew about the fault. I guess thats the risk you take buying old cheap cars. Still annoying tho!!! I do have videos/photos of some of the above mentioned issues if people would like to see. Currently the car is working as it should after doing the neg terminal trick, but it clearly will return.

 

Thanks in advance. 

 

 

 

Hi Matt, the problem is extremely likely to be water getting in to the 'General Electronics Module' (GEM) on later models it has been superseded by the 'Body Control Module' (BCM).

On many cars like yours there is a known issue of water getting in to the connectors of the GEM, leading to corrosion of the connector pins and even damage to the components in the module.

The GEM is part of the passenger compartment fusebox, so before investigating the problem it is very important to disconnect the negative lead from the battery.

Remove the connectors from the GEM and check for signs of water ingress. Look especially for greenish corrosion of the pins. The normal issue of the water getting in to the GEM is from the screenwash pump. The water leaks from the pump and is drawn along the wires by capillary action until it eventually reaches the connector of the GEM.

OR ...........

The problem is a fault with the soldering of the instrument cluster. A quick test to see if the problem is being caused by dry solder joints on the IC is to give the top of the dashboard a firm thump with your hand just above the instrument cluster when the fault occurs. If the fault immediately changes then you have the other known issue of the faulty IC module. There are companies who repair them for about £90, just look on eBay.

1 hour ago, unofix said:

Hi Matt, the problem is extremely likely to be water getting in to the 'General Electronics Module' (GEM) on later models it has been superseded by the 'Body Control Module' (BCM).

On many cars like yours there is a known issue of water getting in to the connectors of the GEM, leading to corrosion of the connector pins and even damage to the components in the module.

The GEM is part of the passenger compartment fusebox, so before investigating the problem it is very important to disconnect the negative lead from the battery.

Remove the connectors from the GEM and check for signs of water ingress. Look especially for greenish corrosion of the pins. The normal issue of the water getting in to the GEM is from the screenwash pump. The water leaks from the pump and is drawn along the wires by capillary action until it eventually reaches the connector of the GEM.

OR ...........

The problem is a fault with the soldering of the instrument cluster. A quick test to see if the problem is being caused by dry solder joints on the IC is to give the top of the dashboard a firm thump with your hand just above the instrument cluster when the fault occurs. If the fault immediately changes then you have the other known issue of the faulty IC module. There are companies who repair them for about £90, just look on eBay.

Yep, it appears to be the issue. There's not a lot there, but there is some. Someone said a similar thing on a Discord server I am in so I checked it out earlier.

 

Here are some photos.

 

 

Do you think cleaning the contacts and plugs would do the trick or do you think water has got into the actual board?? Do you think there's enough damage there to cause the issue?

Thanks so much for getting back to this thread @unofix!

seems to be an issue with the photos. Is the file size too big ?

2 hours ago, M.J. said:

Do you think cleaning the contacts and plugs would do the trick or do you think water has got into the actual board?? Do you think there's enough damage there to cause the issue?

I also can't see the photos, are they on a cloud server that does not allow upload to a (3rd party) site like this?

If the water has not been present too long, and the pcb can be cleaned & dried using alcohol (IPA or just meths), leaving it looking undamaged, then there is good chance it will work again.

If any of the IC pins or solder joints look corroded after cleaning, then it is not so good. It takes very little corrosion to wreck a pcb.

The slightly better news is that the BCM / GEM can be swapped for a 2nd hand one from a near identical car - it must have the same feature / option list unless you can use ELMConfig to re-configure the BCM. But at least it does not have the PATS & security problems that you would get with changing the ECU or the IC.

1 hour ago, unofix said:

seems to be an issue with the photos. Is the file size too big ?

 

51 minutes ago, Tdci-Peter said:

I also can't see the photos, are they on a cloud server that does not allow upload to a (3rd party) site like this?

If the water has not been present too long, and the pcb can be cleaned & dried using alcohol (IPA or just meths), leaving it looking undamaged, then there is good chance it will work again.

If any of the IC pins or solder joints look corroded after cleaning, then it is not so good. It takes very little corrosion to wreck a pcb.

The slightly better news is that the BCM / GEM can be swapped for a 2nd hand one from a near identical car - it must have the same feature / option list unless you can use ELMConfig to re-configure the BCM. But at least it does not have the PATS & security problems that you would get with changing the ECU or the IC.

Oh strange, I just pasted the photos in and they appear for me. I've linked below to the photos directly from my google photos.

https://photos.app.goo.gl/MJhqXT5rNioPWZVbA

https://photos.app.goo.gl/QbDZyan6bykvjs8i6

https://photos.app.goo.gl/iURkN6hBFxe4Qi8F7

https://photos.app.goo.gl/ZMf1A1wW91VmpcqX9

 

 

As for replacing the BCM/GEM, that's good to know as I wondered if it had to be reprogrammed or not. Definitely something to look into as it would be an easy ish fix to replace. However, I imagine water might continue to trace down the wires. 

 

Thanks for all the advice guys. Its been very helpful! 

Followed the links and can see the photos now.

You may be lucky the damage doesn't look too bad.

Clean them up and give them a spray with WD40. You should also consider replacing the screenwash pump as there is a very good chance that it is the source of the water.

1 hour ago, M.J. said:

However, I imagine water might continue to trace down the wires.

Oddly, the two photos of connectors on the BCM are C96 (bigger one) which goes to the washer pump, among quite a few other things, and C98 (smaller, 14 pin one) where 3 of the central pins (the most corroded ones) go to the front Dome light. C98 also goes to the sunroof & rain sensor (if fitted). All these are potential sources of water tracking down cables.

I can't find a pin-out of C96, so can't locate the washer pump wires, they should be pin 9 (Yw/Bk) amd pin 6 (We/Bk). Looking at the photo of the mating connector, it does look like pin 9 has corrosion up inside it.

You would need to remove the casing to properly clean the pcb, there is a very complex electronic module under there. I have not dismantled mine (if it works, don't poke about with it, is one of my mottos, at least with complex expensive stuff anyway!), so can't tell how easy this is. But water damage to these units is very common. It can also drip down inside the dash from windscreen leaks, or even a/c condensation, sometimes.

21 minutes ago, Tdci-Peter said:

Oddly, the two photos of connectors on the BCM are C96 (bigger one) which goes to the washer pump, among quite a few other things, and C98 (smaller, 14 pin one) where 3 of the central pins (the most corroded ones) go to the front Dome light. C98 also goes to the sunroof & rain sensor (if fitted). All these are potential sources of water tracking down cables.

I can't find a pin-out of C96, so can't locate the washer pump wires, they should be pin 9 (Yw/Bk) amd pin 6 (We/Bk). Looking at the photo of the mating connector, it does look like pin 9 has corrosion up inside it.

You would need to remove the casing to properly clean the pcb, there is a very complex electronic module under there. I have not dismantled mine (if it works, don't poke about with it, is one of my mottos, at least with complex expensive stuff anyway!), so can't tell how easy this is. But water damage to these units is very common. It can also drip down inside the dash from windscreen leaks, or even a/c condensation, sometimes.

It works currently, but thats only after resetting all computers by disconnecting battery. If it re-occurs, I might just take it to a garage to sort now I've cut down the diagnostic time (as they said it could take upto 5 hours which I wasnt willing to spend).

No sunroof or rain sensor fitted.

I've not noticed any leaks but the AC does blow really cold (nice for this warm weather) so possibly condensation. Who knows?!

1 hour ago, unofix said:

Followed the links and can see the photos now.

You may be lucky the damage doesn't look too bad.

Clean them up and give them a spray with WD40. You should also consider replacing the screenwash pump as there is a very good chance that it is the source of the water.

I will look into that, thanks. I was thinking of getting some contact cleaner to clean them off. 

13 hours ago, M.J. said:

contact cleaner

Just be careful using contact cleaner like servisol it can attack some of the plastics used on the connector.

3 hours ago, unofix said:

Just be careful using contact cleaner like servisol it can attack some of the plastics used on the connector.

Fair enough, I have some of this halford stuff already from an unrelated project (not car related). It doesn't have any warnings about plastic on it but not sure. 

 

https://www.halfords.com/motoring/engine-oils-and-fluids/lubricating-and-penetrating-oil/halfords-electrical-contact-cleaner-500ml-621335.html

 

Personally I'd feel safer using IPA : https://www.amazon.co.uk/Isopropanol-Alcohol-99-99-Pure-Chem/dp/B099SFWTPW/ref=asc_df_B099SFWTPW/?tag=googshopuk-21&linkCode=df0&hvadid=536027748845&hvpos=&hvnetw=g&hvrand=14130276670791826485&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1006688&hvtargid=pla-1495226446797&psc=1

and then finishing the job with a squirt of WD40 as it repels water.