Central locking

Post Fri Apr 01, 2005 9:03 pm

Ok, where's the first place to start? My central locking doesn't work, from anywhere... & my electric mirrors don't adjust. I've got all the working bits on the ol' 320 so where do I start swapping?
I've had a play with the connector on the driver's door as I suspect that may be the reason for the mirrors? No luck yet though & doubt it's behind the locking though as it should work from the other locks?

Cheers!

Post Fri Apr 01, 2005 9:41 pm

You gone and treated yourself to a 325i Convertible you naughty boy?

Looks really nice in your other post...!

Post Fri Apr 01, 2005 11:43 pm

Most common cause for completely dead central locking IS the drivers door pillar plug/socket.
Check for power with a 12V lamp on the red/black wire going into the central locking ECU.
This wire, on route from fuse 27, goes into the driver's door, round a loop of wire, and back out again to the interior light delay module socket and then to the locking ECU.
Find both red/black wires at the back of the door pillar socket, cut them off, and solder them together, insulated by a bit of heat shrink.

For the mirrors, first check for power (with a 12V lamp) at fuse 19, with the ignition on. (Touch the fuse wire in the fuse with the test lamp lead). Next, pull out the mirror switch and check for 12V on the green/white wire.
If there's power at the fuse, but not on the switch, then door pillar plug again.

Post Sat Apr 02, 2005 11:08 am

Geeman wrote:You gone and treated yourself to a 325i Convertible you naughty boy?

Looks really nice in your other post...!

I have indeed, & it's even nicer in the metal!!

More pics will be taken in the sun today!

Brianmoooore wrote:Most common cause for completely dead central locking IS the drivers door pillar plug/socket....

Cheers Brian! That'll be my first job for today then!

Post Sat Apr 02, 2005 8:29 pm

Brianmoooore wrote: Check for power with a 12V lamp on the red/black wire going into the central locking ECU.
This wire, on route from fuse 27, goes into the driver's door, round a loop of wire, and back out again to the interior light delay module socket and then to the locking ECU.
Find both red/black wires at the back of the door pillar socket, cut them off, and solder them together, insulated by a bit of heat shrink.

Hokay, I haven't fixed them yet, but it looks like the mirrors are indeed down to that plug...

As for the central locking, the 2 black/red wires have already been joined!! There's power there, and at fuse 27, but I have to admit complete ignorance as to where the CL ECU even is!

Help?!

Post Sat Apr 02, 2005 8:57 pm

You won't find it by accident, unless you follow the wiring.
Remove the driver's footwell loudspeaker, and unclip a black plastic plate in the door pillar below it. Unscrew a couple of screws inside the car directly below the speaker hole and pull the ECU out from the cill by the wiring. The delay unit for the interior light also lives in here if you have one fitted.
Open up the ECU and check for water damage. Also check the thermal fuse in the bottom corner of the PCB. (Consists of a resistor with the end of a small leaf spring soldered to it. Resistor overheats because of fault or too frequent use and melts solder).

Post Sun Apr 03, 2005 1:42 pm

Hokay, I found it, & plugged it in (!), but no joy... & nowt with the ECU from my other car either

Any more ideas?

Post Sun Apr 03, 2005 2:53 pm

If the supply's getting to the ECU (pin3), and the earth's OK (brown, pin 4) , and a known good ECU doesn't work then the door plug sockets must be suspect
Check the locks themselves by disconnecting the ECU,and finding the blue wire (pin 1) and the white/brown wire, (pin 2). Earthing one of these pins and applying a 12V pulse to the other should make the locks lock or unlock.
OPEN A WINDOW before doing any work on locks.

Post Sun Apr 03, 2005 3:17 pm

Brianmoooore wrote:If the supply's getting to the ECU (pin3), and the earth's OK (brown, pin 4) , and a known good ECU doesn't work then the door plug sockets must be suspect
Check the locks themselves by disconnecting the ECU,and finding the blue wire (pin 1) and the white/brown wire, (pin 2). Earthing one of these pins and applying a 12V pulse to the other should make the locks lock or unlock.

I'll get back to it; Cheers!

OPEN A WINDOW before doing any work on locks.

Or have a car that the roof comes off!

Post Sun Apr 03, 2005 3:42 pm

Brianmoooore wrote: Check the locks themselves by disconnecting the ECU,and finding the blue wire (pin 1) and the white/brown wire, (pin 2). Earthing one of these pins and applying a 12V pulse to the other should make the locks lock or unlock.

Doesn't do anything

The ECU works in the other car, & the supply & earth are fine... so it looks like the problem lies with the locks? Or at least those blue & white wires! What's the next step?

Got the mirrors working now though

Post Sun Apr 03, 2005 11:28 pm

Blue and white wires go to multiway soldered joints in the loom and from there to all four doors, the boot lock and the fuel filler flap. Seems unlikely that all these should fail together.
Try leaving the ECU unplugged and pulling the plug off the fuel filler flap solenoid. Earth the white wire and apply a 12V+ pulse to the blue wire. This should again lock all the locks. Earth the blue and apply 12V to the white to unlock.

Post Mon Apr 04, 2005 5:14 pm

Yippee!!

It all works... I had to swap all the solenoids over though!! Only the filler flap one was connected & they were all jammed solid... 's all cool now though, but my 320's even less happy than it was yesterday!

Cheers Brian...

Next thing's the front fogs; any ideas on where to start for them!? The only things that won't work then are the headlamp washers (I'll get to em eventually), & the funny security/magnetic lock thingy...

Post Mon Apr 04, 2005 6:35 pm

For the fogs, the connectors at the lights get a fair bit of road crap on them, so check for power here with a lamp first, then at fuses 28 and 29, then pull relay K8 (if it's there at all!), and link pins 30 and 87 (fogs should light). Check relay K8 clicks when the foglights are turned on.

Post Tue Apr 05, 2005 10:31 pm

You really are useful yaknow Brian!!

Definately owe you a pint at a meet sometime!

Anyway, on investigation of my fogs, the right hand one lights about half way through the travel of the switch, but goes out by the time the switch is fully depressed! Is it possible to get inside the switch to clean / fix it, or do I just get a new one? I would have looked already, but I've been busy fixing this ****ing computer! & I'm guessing the left one's just gonna be a connector / bulb - I'll sort that tomorrow.

Cheers

Post Tue Apr 05, 2005 10:54 pm

New switch would be best/mosrt reliable/most expensive option, but they sometimes respond to a dose of proper switch cleaner (Servisol super 10 or similar), sprayed in from the front between the button and the casing, followed by working the switch several times.
Allow an hour to dry, and spray in a little silicon grease to finish the job properly.
This should work on switches that are dirty or the contacts are tarnished, but won't work if the contacts have begun to burn up.

Post Mon May 02, 2005 1:36 pm

Aaaargh! Central locking's died again. It locks fine, but doesn't unlock from anywhere... Any ideas? If it's that blimmin door connector again, any idea which pins are likely to be at fault?

Cheers

Post Tue May 03, 2005 4:29 pm

BTTT

I don't really want to have to start pulling things apart to unlock the filler cap, so it's getting a bit urgent!

Post Tue May 03, 2005 11:51 pm

you should be able to slide the locking mech for the fuel cap open form inside the boot...

just remove any trim panels from the wing in the boot and you should feel a slider about 9" long-slide it towards the rear and the cap will be open

Post Wed May 04, 2005 12:09 am

320Touring wrote:you should be able to slide the locking mech for the fuel cap open form inside the boot...

just remove any trim panels from the wing in the boot and you should feel a slider about 9" long-slide it towards the rear and the cap will be open

Yeah I know... thanks anyway! I just don't really wanna be doing that every time I have to fill up!

Post Thu May 05, 2005 12:27 am

Bump!

Post Thu May 05, 2005 10:32 pm

Somebody?! Anybody?!

Post Thu May 05, 2005 10:54 pm

The same wires to the locking solenoids are used for locking as unlocking. The difference is just that the polaroty is reversed, so it's probable this circuit is OK.
The locking ECU is told to undo the locks by grounding either pin 6 (green/blue) or pin 9 (green/purple). Try touching either of these pins to ground with a short piece of wire and see what happens. If nothing, then I would suspect the ECU.

Post Thu May 05, 2005 11:07 pm

Thanks again Brian

Post Thu May 05, 2005 11:34 pm

...but if the central locking has locked the doors but won't unlock, you should still/always be able to unlock the drivers door with the key...I think. Unfortunately mine doesn't

Hope you get yours sorted Ziggy, mine have been a pain in the ar*e for months!

Post Fri May 06, 2005 12:53 am

Danstable wrote:...but if the central locking has locked the doors but won't unlock, you should still/always be able to unlock the drivers door with the key...I think. Unfortunately mine doesn't

Hope you get yours sorted Ziggy, mine have been a pain in the ar*e for months!

I'm sure I will - I've swapped all the actuators so far, so there can't be much left to do!

I bet it's that blimmin door multi-connector...

Have you tried just disconnecting the actuator from your lock?

Post Fri May 06, 2005 6:51 pm

hate to hijack but im having a similar problem with the lock on my drivers side. it will unlock but wont lock. ive changed the solenoid so it aint that. all the others lock/unlock ok apart from the filler flap (wont do either)
if i try to lock the passenger door it locks then unlocks straight away

any ideas?