Central locking gremlins (Now Sorted)!

[Doggy]

Thought I'd share my experiences so far in attempting to sort a glitch in the central locking on my bro's 53 exec estate, (aka 'The Bangor Banger'). viewtopic.php?f=5&t=22572
It had a declared fault when he bought it - the c/l would fail to lock sometimes. Initially it was a very minor problem, rarely going wrong, but became a pain in time. The battery was on its last legs so we hoped a new one might help, but of course it didn't.
The diagnostic message says, "Intermittent Fault: Right hand door lock"
Swapped the drivers door lock assembly for a spare kindly provided by GingerMagic, but it made no difference - it still works sometimes but not others.

We noticed that the passenger door sometimes fails to operate the courtesy lights and wondered if this might be related?
My Haynes BOL states that the courtesy light switches are part of the door lock on later models......
The diagram shows 3 separate contacts within the front door locks, only one in the rear door locks and none in the tailgate. I surmise this means:
1. The front door contacts:
a). Tell the BSI it's locked
b). Signal the BSI if the locked is operated mechanically, (key or internal locking lever)
c). Tell the BSI if the door is open?
2. The rear door contact tells the BSI it's locked, (or maybe the door is open)?
3. It doesn't know if the tailgate is locked, (probably knows the tailgate's open via the luggage compartment courtesy light switch).

So I'm thinking I have tried swapping the wrong lock.

Anybody had any similar experiences or is able to cast any light on exactly how it's supposed to work?

Incidentally, his MFD shows a graphic image for any door open, including tailgate and bonnet. (I'm pretty sure both of mine only have a graphic display for the four doors and a text message for the tailgate not shut if the car is moving). When the courtesy lights don't come on with the front passenger door open, the door open is not shown on the MFD either.

[steve_earwig]

Just looking Sedre (seconds left until I have to collect t'wife)
a) Door shut
b) Door lock command
c) Deadlock command (does this work on the key?)

No lock signal from tailgate.

Sedre seems to confuse left and right, passenger and driver's side all the time, so I don't think it'd be such a surprise if PP did too.

Must dash. Argh! The car's in the garden! Where's that stinky little dog?

[Doggy]

Thanks Steve.

I think I'll have a go at t'other side. (Non monsieur, c'est l'autre droit).

[scoopeydiesel]

I have a post up there somewhere about a similar issue with the central locking. When i opened the door it would not register on the mfd and no interior lights coming on. Problem was corrosion on the actuator inside the door panel (white box with red plug by door lock inside door card). I used a nail file to clean contacts on actuator and worked perfect. No need to take out actuator, clean with file and check.

[Doggy]

Thanks scoopy - I looked at your post.
Just to clarify, do you mean the pins on the multipole connector onto the lock assembly, or are you refering to the internal switch contacts?
(I'm guessing the first of these).

[scoopeydiesel]

I am refeering to the pins on multipole connector which is the white box with the red plug at the back of the door lock. I just cleaned the pins with a nail file as there was some corrosion on them. Hope it works for you.

[Doggy]

I didn't clean the pins up, but I did connect and disconnect it a dozen or so times in an effort to get the same result.

Trouble is it might have been a bit better for a day or so.... No doubt I'll be having another look at this in due course.

[Stenasev]

Hi,

Similar to what has already been written but I had locking issues, would lock then unlock straight away. Also front windows were hit and miss whether they worked or not. Both of these problems only happened intermittently and not often enough to investigate immediately.

When I got down to it the fault was very light corrosion on the white and/or green multiplugs where the door loom enters the car.

I could replicate the fault by pulling on the loom or wiggling the connectors. Now they are cleaned and greased up all is good and I can't replicate the fault anymore.

Cheers,

Steve

[Doggy]

That's interesting, thanks Steve.

Whereabouts do you get access to those connectors - behind the trim at the bottom of the 'A' pillar?

[Stenasev]

Whereabouts do you get access to those connectors

Well there lies the problem. Access is a bit of a bitch. I initially planned to replace the door loom because I suspected a break in the wire due to the nature of the fault. So I attacked it from the door side. They are right where the loom goes through the bodywork. The rubber loom cover and two multiplugs are connected to a plastic ring. I still haven't got it together properly as other jobs have distracted me

[Doggy]

Access is a bit of a bitch. Naturellement.

Figures. I'll check it out anyway, thanks.

[Doggy]

The saga continues.........

As I said previously, we had noticed the interior lights mostly weren't coming on when opening the front passenger door, so we investigated that today.
Removed the trim, disconnected / reconnected the multiplug on the lock assy a dozen or so times, tried it & it locked / unlocked, 50 times on the trot perfectly.
Opened & closed the door loads of times, lights came on every time.
Another cycle of locking / unlocking from the plip, key in the locks, interior buttons, perfect every time.
Refittted the trim, opened & closed the door, interior lights don't come on.

The infuriating thing is the inability to positively eliminate and part of the system. Then I had an idea.

Kelvin, very kindly gave me a spare driver's door lock, which obvioulsy won't fit the passenger door, but the connector's the same so if you plig it in, the car doesn't 'know' the lock's not fitted to the door. (It senses door open correctly and goes through the locking / unlocking cycle pefectly with the spare lock dangling from the wiring). So we've left the spare lock behind the door trim connected electrically, but not mechanically. This means he has to lock / unlock the passenger door manually, (like wot us old codgers did for years), but the rest of the car works on the c/locking. He's going to use it like that for a week.

I figure if there are only two possibilities:

1. (no hiccups), we need to replace the passenger door lock unit.
2. (still plays up), we have at least eliminated the door lock.

Exciting isn't it?

[steve_earwig]

Indeed, I'll certainly be tuning in next week

[rwb]

And thus whatever remains, however improbable...

[steve_earwig]

Whatever remains is the other two door locks, Sherlock.