AU BCM problem - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

ejute · 10-04-2005, 01:01

I have recently replaced a door lock on the passenger side front because it was not locking.

When I tryed to lock the car it would give me the 3 clunks from the central door locks followed by the beeps from the horn just like a door is open.
Anyway I found it was just the door central locking actuator was stuffed.

Now that I have replaced the lock, it locks OK but when you unlock it, it sounds like the central locking is trying to release 3 times/clunks and after it has been unlocked any time you open any of the doors it does the same thing ie. 3 clunks??

I removed the fuse for the BCM thinking that it may need a reset but it's still the same??

Any ideas ??

thanks Mark

351cid · 10-04-2005, 03:36

i have an industry magazine here that has an artical on this.

i dont have a scanner so i will try to translate.

AU1 , sept `89 - may `00.
original passenger door actuators currently unavailable and AU11 used instead.
the original actuators have a wire that provides the BCM with feedbacksignalthat lets it know that the door is locked.
AU11 actuator is missing feedback signal switch.
BCM no longer recieves door locked signal from passengers door.
it will then pulse the door locks three times to try and ensure that the door is locked.

the wiring can be changed to use the drivers door to provide the signal to the BCM.

they have a diagram that i will try to describe....................

find the BCM behind the dash under the instrument cluster , near the drivers left knee.

the BCM has 2 connectors , one connector ( A ) has 26 wire spots and 2 locator notchs on one side and 6 locators on the other.
one end (#call it the top ) has 4 wires spots offset to the rest and the other end has 6 offset.

start at the top and count 3 wires down on the side with the 6 locaters, should be the first of the not- offset spots, this should be a RED WIRE called -A3 .

next go to connector B ...... 22 wire spots .

need to find the YELLOW WIRE here called B20 .
it should be the 3RD from the end that has 2 offset wire spots ( bottom ) and will be on the side of the connector that has the 2 locator notches.

it says the colours are usually right but the position in the plug is most important.

now that you have the right wires , you need to cut the RED A3 wire and join the connector end of it to the YELLOW B20 wire.

tape up the other end of the RED A3.

this will mean that the central locking will no longer work from the passengers door.

i hope that you can understand this.
iff you are not confussed by now you should be able to handle the job ok

ejute · 10-04-2005, 12:44

Thanks the info!!!

When I pulled the door lock electrics apart I did notice a small button that is operated by the lock when it latches over.

I also noticed on the parts box of the new one that the first letters on the box are AU3xxxxx and wondered if there had been some changes to the part.

Thanks again Mark

ejute · 10-04-2005, 13:24

I have just had a closer read of your reply and noticed that you mentioned that the door locks pulse 3 times to try to ensure that the door is locked.

The problem I am having is it pulses 3 times when unlocking and when unlocked it pulses 3 times when any door is opened.

When locking it just does the 1 pulse/operation like it would normally.

Thanks Mark

351cid · 10-04-2005, 15:24

could still be the same cause.

not sure if it would use the same wire for lock and unlock??

might be worth calling the ford service dept to see if they will check the wire diagrams .
may need to do the same procees with different wires.

ejute · 10-07-2005, 18:12

Problem resolved!

After some close inspection it was the little internal switch that tells that BCM that the lock is either on or off that is missing form the new replacement lock.

The plug on the new lock has 4 wires in it and the lock on the old lock has 5.The 2 wires that go to the switch 1 goes to the plug and the other connects onto the black wire that goes to the switch that is operated by the door opening handles.

Instead of modifying the BCM wiring I just fitted the old switch into the new lock.

I have taken a photo of the 2 lock actuators side by side and will be asking Mr Ford to please explain!!

I paid close to $150 for a genuine replacement part that did not work properly.Not happy Jane!!

Many thanks to "351cid" you pointed me in the right direction.

Cheers Mark

351cid · 10-07-2005, 19:27

good to hear you got it working.

any chance of putting the pics on here so we can have a look for future referance.

ejute · 10-11-2005, 00:41

Sorry, it has taken me so long to post picture this I had to get my appendix removed....bugger!

New one is on the right old one is on the left and still has that annoying little switch mounted in it.

Cheers Mark