GEM module testing/replay

[Phil3186]

Hi all, so I have a 2008 1.25 fiesta zetec I bought for my son to learn in for his driving test etc, the stereo has been a bit hit and miss working up to now but after the battery went flat and my son took the battery off to charge it and put it back on ‘negative first’ the car went mental and the hazards were on permanent, folding mirrors doing thier own thing, the central locking going off all the time and the boot lock popping open, all while the engine was running and no one was touching the car. After a bit of Googling I’m lead to think the GEM module may have been fried when connecting the battery, does anyone have any experience of buying a second hand GEM module and it working once fitted? 
we have tried disconnecting the battery and following a proper reconnecting procedure but the indicators, folding mirrors and boot release still won’t work, I’m happy to buy a new (old) GEM module off eBay but thought I’d reach out to see if anyone had any thoughts on any other checks to make first? 

[unofix]

It's not as simple as just replacing the GEM. First you have to find a unit with the exact same part number. The last letter can be the same or higher than the original, but it can't be lower.

Next the GEM will require programming with the vehicles "AsBuilt" files. Finally you shouldn't need to but it may become necessary to reprogramme the car keys back in. This stage normally isn't needed as the key id is stored in the instrument cluster.

If you fully disconnect the car battery (both leads) and then short together the positive and negative leads on the car for a minute before reconnecting the battery it may reset all the vehicle modules.

[Phil3186]

Quick update, I found a GEMA Module on eBay with the same part number (£40) as I figured it was worth punting £40 on and crossing my fingers before getting garages involved,

got the old unit off after a few choice words at the right hand side screw! Fitted the new one, connected the battery and so far it seems to have done the trick, as unofix mentioned the keys needed reprogramming but other than that it’s solved the problems I had and now the rear heated window even works again when it didn’t before!
the only issue I now have is the cars convinced the bonnet is open when it isn’t now. Fully working cars are boring though, right? 

[unofix]

The bonnet open fault is a very common problem. The switch on the bonnet catch fails or gets stuck. Give it a good blasting with WD40 and it might just clear the fault.

[Phil3186]

5 hours ago, unofix said:

The bonnet open fault is a very common problem. The switch on the bonnet catch fails or gets stuck. Give it a good blasting with WD40 and it might just clear the fault.

Thanks! Where is the sensor on the catch? Had a good look and it all looks mechanical, I’ll take it off next weekend and give it a good clean up and see if that works!

[unofix]

It will have a connector.

[Phil3186]

On 5/14/2023 at 11:19 PM, unofix said:

It will have a connector.

Thanks for the pics, I think mine may be an older design being a mk6? I haven’t taken it off yet but mine looks much more like the one in the pics I’ve added, I can’t see a connector or wire coming from the catch? I’ve looked for a bonnet switch like one of my Old Ford’s had, but again can’t see anything? Am I missing something obvious?

[TomsFocus]

12 hours ago, Phil3186 said:

Thanks for the pics, I think mine may be an older design being a mk6? I haven’t taken it off yet but mine looks much more like the one in the pics I’ve added, I can’t see a connector or wire coming from the catch? I’ve looked for a bonnet switch like one of my Old Ford’s had, but again can’t see anything? Am I missing something obvious?

Not all of the Mk6's had an alarm, and as such no bonnet warning sensor.  For the ones with an alarm, the sensor is in the latch, like this.

Genuine Ford Fiesta MK5 Bonnet Catch Latch 1478992 | eBay

 

[unofix]

On 5/14/2023 at 4:51 PM, Phil3186 said:

the only issue I now have is the cars convinced the bonnet is open when it isn’t now.

The OP has replaced the GEM. I'm wondering if his car doesn't have an alarm system, but the replacement unit came from a car that did.

If that's the case he will need to find the output on the replacement GEM and link out the bonnet open connections. Or it maybe possible to simply use FORScan and alter the settings in the GEM to 'No Alarm'

[Phil3186]

Thanks guys, I haven’t had a chance to remove and clean the latch yet but if that doesn’t solve it then I guess the donor car having an alarm and mine not having an alarm is the thought I’m having, I’m not sure how anyone would go about linking connections on the gem, or even know what pins it would be etc so I guess options are

1- buy another gem unit with matching numbers and hope it is from a car without an alarm

2- find a auto electrician who knows how to code things out like the alarm setting, or somewhere I can send both units away too to be looked at