Boot Release Not Working, Possible Ecu Fault?

[matt kingston]

Hi all, just got a mondeo and trying to work out what's wrong with the dash boot release, it doesn't work and nor does the tailgate release.

Iv done the obvious and checked the switches, they all give good continuity when pressed nd don't seem to be shorting, iv disconnected the tailgate switch as suggested and no dice...

The fob will open the boot so the boot servo and wiring must be fine and id assume the ecu is doing it's job however all connections to the ecu via pin 2 and into the ecu plug are all fine, iv tested them so maybe the ecu isn't responding to the release switches but it is responding to the fob......?

Confused to say the least.

Any help would be much appreciated.

Many thanks.

[troy45]

Sounds a strange one - have you got access to a wiring diagram to spot any difference in the circuits as to why the hard wired switches don't operate the tailgate but the fob does.

If the GEM module is upset you could try a battery reset, and maybe worth checking all the connections to it plus fuses?

[Dan62]

The attached might help.

Don't confuse the ecu with the GEM, the GEM connectors are coloured and its the Brown connector that the signal from the switches goes to.

Check the wire between the switch and the GEM. The GEM is in the Right hand A pillar.

[matt kingston]

Yes ibcan confirm good earth via both switches right into the center connector of the gem, even the actual pin in the connector gives good feed to ground so this a must be ok, the fob opens boot so the 12 pulse from the gem to the release mech must also be working as it should.

I'm wondering if there's to feeds to the boot release mech, one for fob use and another wire for the manual release switches etc... Seems odd to do that tho...

[Dan62]

The GEM is the receiver for the fob so there are no other wires or boxes associated with the release.

Looks like the GEM then.

[matt kingston]

Ok so is the gem a straight swap with no config required? Obviously I need to match exact unit model numbers...

[troy45]

Unit numbers would likely need to have same part number though the last letter of the part suffix (2 letters at end) can vary as this is showing different design levels of the same variant. I think you'd need a specific software file also loading (CCF) to go in on top of any software already in the GEM

Could be that Ford supply 1 spec of unit for service which covers all models, so this might have different part number than explained above.

[Dan62]

This may be a longshot but its possible that the unlock switch in the drivers door could be inhibiting the switches and only allows the fob to operate the tailgate.

Got to be worth checking out the Black/Green wire going to C428 pin 16 is grounded

[matt kingston]

Ok I guess the black green wire should only be grounded when the drivers door unlock switch is pressed?

And your not rfering tongue window lock button are you?