Endless Locking
05-28-2003, 12:22 AM
#1
Intermediate
Thread Starter
Join Date: Feb 2003
Location: dallas
Posts: 45
Likes: 0
Received 0 Likes
on
0 Posts
Endless Locking
Having an odd problem on the 928 i just picked up. The central locking system when activated via the dash control endlessly cycles...lock...unlock...lock...unlock...lock...unlock...until the ignition is turned off.
Eveything works...TOO WELL. Just the endless cycle. Things work properly when the door locks are used to activate the central locking.
Any ideas?
Chris Magid
1986 928s Garnott Red
camdsl@swbell.net
Eveything works...TOO WELL. Just the endless cycle. Things work properly when the door locks are used to activate the central locking.
Any ideas?
Chris Magid
1986 928s Garnott Red
camdsl@swbell.net
05-28-2003, 01:08 AM
#2
Cottage Industry Sponsor
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Chris:
It icould be that one of the locks is misadjusted and does not open or close all the way. THen the system thinks the lock process is not completed, and reverses. And so on. It's a matter of figuring out the right adjustment.
Not fun. That's why the newer cars have an electromagnetic system...
It icould be that one of the locks is misadjusted and does not open or close all the way. THen the system thinks the lock process is not completed, and reverses. And so on. It's a matter of figuring out the right adjustment.
Not fun. That's why the newer cars have an electromagnetic system...
05-28-2003, 02:16 AM
#4
Intermediate
Thread Starter
Join Date: Feb 2003
Location: dallas
Posts: 45
Likes: 0
Received 0 Likes
on
0 Posts
Well...what would be the difference between using the console and using the exterior keys?
Should I swap out the whole part? Anyone parting out a 84 to 86 928 with good door locks? Might be overkill...but it would wiggle a lot of wires.
Yeah, this vacuum stuff is for the birds.
Chris Magid
1986 928s Garnott Red
camdsl@swbell.net
Should I swap out the whole part? Anyone parting out a 84 to 86 928 with good door locks? Might be overkill...but it would wiggle a lot of wires.
Yeah, this vacuum stuff is for the birds.
Chris Magid
1986 928s Garnott Red
camdsl@swbell.net
05-28-2003, 03:31 AM
#5
Burning Brakes
Join Date: Apr 2002
Location: Denmark
Posts: 881
Likes: 0
Received 0 Likes
on
0 Posts
Cris,
Use the search facilities and see: <a href="http://forums.rennlist.com/cgi-bin/rennforums/ultimatebb.cgi?ubb=get_topic;f=14;t=006124#000000" target="_blank">http://forums.rennlist.com/cgi-bin/rennforums/ultimatebb.cgi?ubb=get_topic;f=14;t=006124#000000</a>
Use the search facilities and see: <a href="http://forums.rennlist.com/cgi-bin/rennforums/ultimatebb.cgi?ubb=get_topic;f=14;t=006124#000000" target="_blank">http://forums.rennlist.com/cgi-bin/rennforums/ultimatebb.cgi?ubb=get_topic;f=14;t=006124#000000</a>
05-28-2003, 04:38 AM
#6
Cottage Industry Sponsor
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Chris:
No, when you turn your keys, you probably turn further than the electric motors move the locks. If you turn far enough, it won't cycle. If you turn just enough to make the motors react, you might get the same result. Thry that on both sides.
No, when you turn your keys, you probably turn further than the electric motors move the locks. If you turn far enough, it won't cycle. If you turn just enough to make the motors react, you might get the same result. Thry that on both sides.
05-28-2003, 10:18 AM
#7
Banned
Join Date: Feb 2002
Location: Ft. Lauderdale FLORIDA
Posts: 5,248
Likes: 0
Received 4 Likes
on
3 Posts
I've had the dancing door lock syndrome for years. Recently, I was able to solve the problem permanently!
-Remove your door panels carefully. Near the top of the metal door frame you will see a wire that is held down with gray plastic straps. This wire leads to the door lock servo. Using a small flat blade screwdriver, gently pry the wire connector from the bottom of the servo.
Carefully re-attach your door panel, and perform the same to the other side. You'll now find that your locks work perfectly- no more stupid cycling that makes your car look like an idiot and raises your blood pressure. You'll get the added benefits of a tiny amount of exercise when it comes time to unlock the passenger-side door as well.
Good luck-
Normy!
'85 S2 5 Speed
-Remove your door panels carefully. Near the top of the metal door frame you will see a wire that is held down with gray plastic straps. This wire leads to the door lock servo. Using a small flat blade screwdriver, gently pry the wire connector from the bottom of the servo.
Carefully re-attach your door panel, and perform the same to the other side. You'll now find that your locks work perfectly- no more stupid cycling that makes your car look like an idiot and raises your blood pressure. You'll get the added benefits of a tiny amount of exercise when it comes time to unlock the passenger-side door as well.
Good luck-
Normy!
'85 S2 5 Speed
Trending Topics
05-28-2003, 02:39 PM
#8
Burning Brakes
Join Date: Aug 2001
Posts: 784
Likes: 0
Received 0 Likes
on
0 Posts
Perfect timing on this thread. I've got yet another variant on the misbehaving locks. Mine usually lock themselves when I turn on the ignition. So the steps are:
- Walk up to the car.
- Unlock it with the key (the central locking unlocks the whole car)
- Open door
- Get in
- Close door
- Insert key in ignition
- Turn on igntion
- All door lock and central indicator "key" button illuminates.
- Press "key" button on center console and the car unlocks and light goes out.
- Start car and drive
The car doesn't always do it. Also, if I unlock the doors while inside the car (with the center console button), then shut off the ignition, then turn the ignition back on, nothing happens - the doors do not spontaneously re-lock.
I'm going to try unlocking the car from the passenger side before getting in to see what happens.
I also poured over the service manuals looking for some help. There is an adjustment procedure to align the door locking motors with the mechanical latches in the doors. I suspect this is the problem. Since the problem only occurs after I've done something to the doors (unlocked the car from the outside), I'm thinking the motor must have some limit switches in it that aren't getting tripped when they should.
I also went over the wiring diagram. In my car ('85) and newer, there's no vacuum anywhere near the central locking. That's a good thing. And the system isn't actually that complex. There's a central locking control unit that basically has several inputs: power and ground, what I think is a trigger from the power window relay (so you can't unlock the car via the console button without the key, I think), and 4 wires to each door locking motor (4 wires out of the control unit split into 8 - 4 to each door lock motor - so the control unit controls the doors in parallel.
The 4 wires to the door lock motor are power and ground, plus 2 "mystery" wires. Since the central locking "brain" controls the power and ground to the door motors, I'm going to go out on a limb and say that each of the mystery wires is a limit switch. One for the "locked" position, one for the "unlocked" position.
My theory about the car where the locks cycle endlessly is that there is a piece of logic in the central locking brain that says "since I can't control the door motors separately, if the door locks are out of sync (one locked, the other unlocked), cycle the system until they're in sync."
But due to switch misalignment in the doors, the switches never satisfy the brain. When the "locked" switch opens on one side, the "unlocked" switch on the other also opens. So the brain thinks it's still out of sync, so it gets stuck in an infinite loop.
In my car, I suspect one of the door's limit switches is flaky. Here's what I think is happening:
- Unlock door with key
- Driver's door unlocks
- Driver's door "locked" switch changes state
- Driver's door "unlocked" switch is broken so its state doesn't change
- Simultaneously, passenger door unlocks because "locked" switch in driver's door changed state
- Passenger door "unlocked" switch changes state because it's not broken
Now the doors are out of sync. Even though they're both physically unlocked, the central locking brain sees the passenger door as unlocked but the driver's door in an "indeterminate" state.
- Turn on ignition
- This sends that "trigger" signal to the central locking brain, which for some reason tells it to get the doors in sync.
- Since one door is unlocked and the other door is unknown, logic dictates that it lock the doors in order to get synchronized
- Motors cycle the doors to the "locked" position
- Both "locked" switches change state
- Central locking brain is satisfied the doors are in sync
- End
The fly in the ointment here is how I can unlock the doors with the button on the center console. And how once unlocked via the center console button, they don't re-lock when I switch the ignition off then on. Unless there's a bug/feature in the central locking computer programming that says "If the doors get unlocked via the center console button, once the "locked" switches change state, that's good enough. Don't wait for the "unlocked" switches before you declare the doors unlocked." Which seems a little weird so I'm just going to trail off at this point...
Bryan
- Walk up to the car.
- Unlock it with the key (the central locking unlocks the whole car)
- Open door
- Get in
- Close door
- Insert key in ignition
- Turn on igntion
- All door lock and central indicator "key" button illuminates.
- Press "key" button on center console and the car unlocks and light goes out.
- Start car and drive
The car doesn't always do it. Also, if I unlock the doors while inside the car (with the center console button), then shut off the ignition, then turn the ignition back on, nothing happens - the doors do not spontaneously re-lock.
I'm going to try unlocking the car from the passenger side before getting in to see what happens.
I also poured over the service manuals looking for some help. There is an adjustment procedure to align the door locking motors with the mechanical latches in the doors. I suspect this is the problem. Since the problem only occurs after I've done something to the doors (unlocked the car from the outside), I'm thinking the motor must have some limit switches in it that aren't getting tripped when they should.
I also went over the wiring diagram. In my car ('85) and newer, there's no vacuum anywhere near the central locking. That's a good thing. And the system isn't actually that complex. There's a central locking control unit that basically has several inputs: power and ground, what I think is a trigger from the power window relay (so you can't unlock the car via the console button without the key, I think), and 4 wires to each door locking motor (4 wires out of the control unit split into 8 - 4 to each door lock motor - so the control unit controls the doors in parallel.
The 4 wires to the door lock motor are power and ground, plus 2 "mystery" wires. Since the central locking "brain" controls the power and ground to the door motors, I'm going to go out on a limb and say that each of the mystery wires is a limit switch. One for the "locked" position, one for the "unlocked" position.
My theory about the car where the locks cycle endlessly is that there is a piece of logic in the central locking brain that says "since I can't control the door motors separately, if the door locks are out of sync (one locked, the other unlocked), cycle the system until they're in sync."
But due to switch misalignment in the doors, the switches never satisfy the brain. When the "locked" switch opens on one side, the "unlocked" switch on the other also opens. So the brain thinks it's still out of sync, so it gets stuck in an infinite loop.
In my car, I suspect one of the door's limit switches is flaky. Here's what I think is happening:
- Unlock door with key
- Driver's door unlocks
- Driver's door "locked" switch changes state
- Driver's door "unlocked" switch is broken so its state doesn't change
- Simultaneously, passenger door unlocks because "locked" switch in driver's door changed state
- Passenger door "unlocked" switch changes state because it's not broken
Now the doors are out of sync. Even though they're both physically unlocked, the central locking brain sees the passenger door as unlocked but the driver's door in an "indeterminate" state.
- Turn on ignition
- This sends that "trigger" signal to the central locking brain, which for some reason tells it to get the doors in sync.
- Since one door is unlocked and the other door is unknown, logic dictates that it lock the doors in order to get synchronized
- Motors cycle the doors to the "locked" position
- Both "locked" switches change state
- Central locking brain is satisfied the doors are in sync
- End
The fly in the ointment here is how I can unlock the doors with the button on the center console. And how once unlocked via the center console button, they don't re-lock when I switch the ignition off then on. Unless there's a bug/feature in the central locking computer programming that says "If the doors get unlocked via the center console button, once the "locked" switches change state, that's good enough. Don't wait for the "unlocked" switches before you declare the doors unlocked." Which seems a little weird so I'm just going to trail off at this point...
Bryan