hi guys
I've a strange one I'm hoping someone has seen before.

My car today decided that it would not let me lock it. When I press the lock button or use the key it will just pop back up, like a door is ajar or open and the horn sounds to warn me. The interesting thing is on the cluster when the car is running it shows all the doors and boot are open (it has actually done this for a while whenever any door was open it showed all and not just the one that's open but I just ignored it.)
All the doors are actually locking as I pulled the battery off after locking with the remote before it could reopen (mainly so no one can break in overnight).

May be complete unrelated but I've just changed from auto to manual and still have the auto ecu (using the resistor trick to replicate the tranny gear selector and temp signal). Been driving like this for a few days with no issue......

Could this just be a faulty door lock mechanism or something more sinister.......

Cheers
Steve

Sounds like a fault door open switch. But aren't these built into the au motors? May need to figure out which one causes it and then swap it out. I had the same issue in my escape - new servo fixed it once I knew which one it was

It's an au3 so you may be able to get the info using forscan and obd2?

Cheers, I'm lucky to have a spare car available so I guess I'll just try each door actuator till it fixes it.

Is the au3 readable with obd2? My au2 was not. If so that will open up some possibilities.

I think it's weird that the cluster shows all the doors open when you driving (I'm pretty sure my au2 Fairmont used to show each door separately when they opened) I'd be pretty confident that all 4 switches didn't fail together......

After fitting AUII wiring to my ED I can confirm that the mid series harness in an AU XR does not have individual door ajar indicator provision... I had to run a wire back from each door to a circuit board I made to do a combination of run the AU BEM and the NL cluster door ajar system...

The BEM/cluster have two door ajar inputs, one is the driver door and the other input is all three doors... If I remember rightly I think it was separate wiring until the dash loom... Once it went through the big white plug the 3 passenger doors joined into one wire and then went into the cluster and BEM, while the drivers door was separate...

If you are showing everything ajar with any one door open then you have a short in the wiring somewhere... It is ground all the three pins out in the cluster... Which is driver, passenger and boot... And if the boot is showing ajar it may be enough to back feed the light and cause the boot light to be on even when it closed? Causing a possible flat battery...

Cheers,
Tim

Found it...

Shows here how on high series the 4 doors remain separate but on XR (low series) the three passenger doors conjoin and trigger the cluster and BEM as one... You would need to separate these wires at the cluster and then add diodes after the cluster to get all three doors into one as the go into the BEM, diodes will prevent the cross talk in the cluster like you're getting now...

Sounds like a passenger door lock problem...

You should be able to identify it id you can access the door plugs easier than pulling trims off and see which one has a ground on that pin all the time... When the doors are open the door ajar wires ground the BEM to tell it to turn the interior light on and also prevent it from lock the doors... When the doors are closed the ground is removed... A multimeter will find this for you easily enough...

Cheers,
Tim

Once again Tim thanks for your help, this whole system is now much clearer.

I did notice that my XR series 3 has the wiring for the Ghia courtesy lighting on the door trims (which made it easy for me to add in my Ghia door cards) which i assumed would have only been on the high series wiring models (i.e. maybe the base forte also has these unused plugs taped up too).

FYI I disconnected my battery overnight as i did not want anyone snooping through my car and when i reconnected it this morning the door signal has disappeared when all the doors were closed so no issue locking it at work today..... I wonder if this just is a loose connection or the body computer is a little dodgy. I will monitor closely and carry a 10mm spanner in case i need to remove the battery terminal.

I have another possibly huge take I'd love to ask you advise about (if i may). My AU2 fairmont which got hit my a tree is sitting in my garage currently being used as a parts bin however I would LOVE to swap over the dash and have the digital climate and trip computer etc. This is so much nicer than the manual dials in my opinion.
Is this simply a matter of switching over the dashes and dash looms or does the body computer need to be changed also (i.e. recoding required)?

I'm up for the task of changing the dashes (I'm always up for a challenge) but i should also be realistic (speaking on my wife's behalf ).

I'm guessing if i switch over the dash I could switch over the loom for the doors at the same time and then have the additional wiring to show the individual doors open?

Cheers in advance.

Steve

I just released i wrote something stupid . The door wiring is the same on both high and low series, its just from the C-50 plug to the cluster that varies so by changing the dash/loom this should incorporate the additional wiring needed.


Cheers
Steve

This just gets weirder and weirder.... I went for a drive at lunch time and now when you are in the car with the car running the dash now shows the doors are shut HOWEVER all the come one when you are driving and stay on . I also noticed that when i park / lock it will now stay locked but the interior lights stay on..... Still had to remove the battery to stop the battery going flat.

Could this be something as simple as a door not registering that its closed but taking a few seconds to loose the connection thus letting me lock the doors first?

Sit in the car and lock it with the remote... If you open a door I'm sure they all unlock?

You have a wiring problem mate and it sounds like you'll be looking for a needle in a haystack to find it... I'd try pulling off all your scuff panels and unplugging one door at a time for a day and see if that isolates the problem... If you see no improvement trying that then you'll be looking for a problem in the body or dash loom...

You could fit a high series dash loom... Pretty sure it requires an entire dash but because the message centre wont fit in a low series dash? It'll require the high series heater box to be fitted... Along with it's loom... That should plug into the high series dash loom, the high series dash loom should plug into any body loom (AU1 is different from AU2/3) and also should plug into PCM harness...

Because you'll then be running a high series BEM to make it work you'll need a PATS reset done to pair the key to the BEM and the BEM to the PCM to make it start again... (Ford or anyone with an expensive scan tool can do this...)

Cheers,
Tim

Thanks again Tim.

I will remove the door cards and unplug each door at a time to see which one is causing the lights to stay on. I'll have a go over the weekend and let you know how i go......

As for the high series dash loom i have a complete series 2 fairmont that i wanted to swap the whole dash over (i.e. with digital climate, trip computer etc) into the XR6. Just so i know what I'm getting into i actually need to change the dash/loom, heater box and loom and switch the low series BEM to the high series (i.e. coding will need to be done at ford)

Pardon my ignorance does the BEM need to be coded to pair with the ECU (is this what you call a PCM?) and keys or just the BEM to keys need to match?.....i can change over the ignition barrel/door keys from the Fairmont to match the high series BEM however the Fairmont ECU is long gone and replaced with an aftermarket one so i cannot do all 3.

Cheers for your help.

Probably easier to unplug the entire door loom? Which you access under the carpet from inside the car... Just remove the scuff plates to find the rear door plugs and kick panels to find the front door plugs? That proves/disproves the entire door loom, not just the motor... Or just try one motor at a time if that's easier... If that fails, then move onto door looms...

PCM is Powertrain Control Module so yes... ECU (PCM is what Ford call it)

All three parts are coded together... Keys, BEM and PCM...

It's called a PATS reset (a Ford technician would know exactly what this is) and this will program all your parts together... When I fitted AU2 gear to my ED I had no keys but matching PCM and BEM so I bought two keys (2 are required) and did the reset... Takes 10-15 mins to go in... When I thought I had a PCM problem and replaced it I had to do another PATS reset to get it to go...

Cheers,
Tim