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No power to sliding door position switch vito w639 2004

Kathvito

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Joined
Dec 21, 2024
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16
Location
london
Car
vito w639
Central locking of my 2004 W639 vito only working on front doors and only unlocks on tailgate. Fuses ok (under seat). Have been checking the connector to the position switch (the connector plates on the sliding door frame (see photo) and I get no power there (blue and red wire I presume). Do the wires come from the fuse box directly or is there anywhere else I can test the power supply? The sliding doors don't have a control unit. The tailgate is difficult to test with the multimetre but I seem to get some reading on the blue and red wire and it does at least unlock remotely. Everything opens and closes manually. I just think there is an electrical problem somewhere and I'd like to find it before I spend money on replacing the door locks. I'd appreciate some advice!
 

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Problem solved, I have current to actuators but central locking on sliding doors and tailgate still not working correctly.
 
If you manually lock all 3 rear doors, do they unlock on the fob?
 
I have taken off the tailgate lock and the little solenoid only unlocks with fob. I could replace the solenoid or the whole lock but I am not sure that this is the answer to the door open beep. I have used the Haynes Autofix wiring diagrams and it tells me to "Measure the resistance between pin 4 (in boot lid lock unit) and A 20 (E6 Power supply control unit). Is it less than 1 Ω?". I presume this is the ecu in the fuse box?? A20 doesn't seem to be a used connection, A19 and pin 3 gave me a resistance reading but nothing on A20. Any ideas??
 
Where is E6 on my vito?? I also have to test F1 and 2 and H 1,2 and 3 on E6. Please help
 

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Is this layout the same as yours?
Being a 2004 it may have the earlier fuse board.
 

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No mine's a A639545010. If I want to test continuity between the door control unit and the SAM, do I have to take it out and test wires underneath?
 
No, the door is fed via the pins and pads on the B pillar.
There is a motor and controller within the rear trim. That's a fair bit o work to remove.
There are pulse signals through to solenoids within the door.
There are micro switches that send open / closed signals to the SAM.
The micro switches are a known failure on these.

I don't know what your E6 relates to.
Some research here and you should find some DIY cct diagrams that may help.
 
Thanks for this answer! I have taken off all the trimmings on the sliding doors and tailgate. I have taken off the tailgate lock and thanks to a really useful video (
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), took it apart and verified that the solenoid is working and the micro switch can function correctly you can see it in the photo with the sliding screw removed. With a power probe, I can lock and unlock. I am replacing the connector to the lock as this seemed a bit dodgy (the lock would only unlock with the fob and one of the 2 power wires seems to have a loose connection, I'm pretty sure that this dodgy wire sends the locking pulse).
I have begun on the tailgate lock as I think I read somewhere that if the tailgate lock is not functioning correctly then the sliding doors won't either.
You mention "There is a motor and controller within the rear trim", I'm not sure what you mean by this.
I can operate the locking mechanism of the sliding doors with my power probe (when the doors are open)

"There are micro switches that send open / closed signals to the SAM" this is what I am concerned about. Is there any way of testing that the wires sending the signals to the SAM are working correctly? E6 is Haynes Autofix's name for the SAM module.

I really appreciate any return on this issue!
 

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Thanks for this answer! I have taken off all the trimmings on the sliding doors and tailgate. I have taken off the tailgate lock and thanks to a really useful video (
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For more detailed information, see our cookies page.
), took it apart and verified that the solenoid is working and the micro switch can function correctly you can see it in the photo with the sliding screw removed.


With a power probe, I can lock and unlock.
Is this a rod, like a screw driver, to manually push the lock levers?
I've used this method to see if the SAM recognises the lock to be closed, that is that the hasp may not be allowing a full travel of those levers within the lock mechanism.
If the lock isn't recognised as locked when using a screw driver to manipulate, then the micro switch is at fault.
I am replacing the connector to the lock as this seemed a bit dodgy (the lock would only unlock with the fob and one of the 2 power wires seems to have a loose connection, I'm pretty sure that this dodgy wire sends the locking pulse).

I have begun on the tailgate lock as I think I read somewhere that if the tailgate lock is not functioning correctly then the sliding doors won't either.
Afaik any of those 3 rear door not being recognised by the SAM as closed, then fob locking of all 3 will be inhibited.
So if the 3 rear doors fail to lock on the fob, I then look to identify which of the 3 rear doors isn't seen as locked.
You mention "There is a motor and controller within the rear trim", I'm not sure what you mean by this.
I'm not sure if you have said, but I have assumed that you have the electric side doors. As I seem to remember you talking of dash controls than you must have them.
With rear trim removed the motor and controller sits behind the rear speaker, if you have those. If not it is near as far forward of the rear side panel as can be. Well tucked in and awkward to remove, especially as the push / pull wire rope is through to the door. These can be popped off the balls on the middle door roller btw.
Water does find its way onto those door controllers. On mine, even after sealing the side window seals, I've fashioned extra protection above them.
I can operate the locking mechanism of the sliding doors with my power probe (when the doors are open)

"There are micro switches that send open / closed signals to the SAM" this is what I am concerned about. Is there any way of testing that the wires sending the signals to the SAM are working correctly? E6 is Haynes Autofix's name for the SAM module.

I really appreciate any return on this issue!

Within the motor mechanism there is a cogged wheel, with slots.
These slots are counted as they pass sensors during the door sliding. I theorise that if there is water bridging those slots, then the counter becomes confused.
If cleaned and then as should be, a couple of open / closed cycles and the system will be counting correctly again. Although there is a resetting of this on Star, I'm not sure it is really necessary to set the door up again.

So, micro switches are often the issue. Namely the micro switch that recognises full travel of the lock pwls.

Water ingress to the controller is worth consideration, and the condition of the controller if it has been wet.

Water on the cog slots upsetting the counting of those slots, just how relative this is is only a guess.

The SAM is very susceptible to water ingress, the drainage under the bonnet and security of the under bonnet fuse, relay, SAM, ECU, TCU enclosure all being critical.

When the SAM is affected I would expect other issues also though, like lights, alarm, wipers becoming erratic.
 
Ah no! my sliding doors are not electric! I am hoping that the SAM is not the issue. Meanwhile I am working on all the rear locks, today one that used to open, now doesn't ... enough to want to pull your hair out!
 
Afaik any of those 3 rear door not being recognised by the SAM as closed, then fob locking of all 3 will be inhibited.
So if the 3 rear doors fail to lock on the fob, I then look to identify which of the 3 rear doors isn't seen as locked.
Sorry that's not clear.

If one of the rear doors is seen as not closed fully by the SAM, then it disables the locking of all three.
They can still be locked from within manually. The fob would unlock all three after this.

The contact pads have a protective coating, that could be removed by scrubbing clean.

The nearside pads can be turned upside down and swapped for the offside.
Be careful to tie off the unplugged plugs, so they don't drop into the pillar.

The pins would then contact onto an unused part of the pads.
 
Ok thanks for explaining the rear locking system. I have new pads and have continuity when the sliding doors are closed. I hope I'll get a positive result when I get the rear lock back in.
 
Ok thanks for explaining the rear locking system. I have new pads and have continuity when the sliding doors are closed. I hope I'll get a positive result when I get the rear lock back in.
You might have said,
have you done a continuity test of the micro switch that is operated by the locking?
I saw mine vary at each operation. Of course it should be able to be zero ohms, allowing for the meter leads.
 

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