V70 Driver's door sensor?

[richardt1994]

Hello All,

My 58 plate V70 has developed an annoying intermittent problem: The driver's door occasionally thinks it is open when it is firmly closed. It brings up the door open warning on the instrument display, turns on the interior headlining lights etc. The only way to "clear" the fault is to fully open the driver's door to its widest extent and the close it again. I have looked all over the door edges for a switch or sensor and cannot find one? This has proved to be more than a pain in car parks when the adjacent vehicle prevents the door from opening fully!

Does anyone know where the door open sensor is located and what type of switch it is? I am assuming from the lack of obvious contacts etc it is a proximity or hall effect switch of some sort somewhere, perhaps in the hinge side of the door or built into the lock assembly? It is odd that fully opening the door clears the fault, as if the door lock at fully open is far enough away from the car body for the switch to reset in some way.

Any and all advice gratefully received.

Richard.

[green van man]

I know on the P1 it was a micro switch in the door lock, rivited on and not available except as part of a new lock from Volvo. Available from maplins etc if you were willing to drill out the fixings and re fix.

Sorry not had need to strip my P3 locks yet.

Paul.

[Cubbington]

Bloody typical, mine's just literally started doing this...after having both passenger side locks replaced last week...

Waiting for Volvo to call me back to see if they can get one in for tomorrow so I can have a go at replacing it this weekend.

Currently got the battery disconnected so I could at least lock the car, as the driver's door lock kept on unlocking itself when the deadlock kicked in...

[richardt1994]

@Cubbington and @GreenVanMan
I started thinking a bit more about this yesterday. On my V70 Fully opening the driver's door until it stops and then closing it seems to temporarily "clear" the fault so I started doubting the sensor/switch as the source of the problem as it is embedded in the latch/lock assembly so far as I know. The signals to and from the door pass through a covered cable loom at the hinge end of the door with a large clip on multi-contact connector on the door. It may be that the cable loom or connector is at fault and fully opening the door "closes" a dodgy connection somewhere in the cable or connector.

I have therefore un-clipped the connector and cleaned all of the contacts as best I can, although there was no obvious sign of corrosion or damage. There are a few posts in the XC90 sections about electric window faults caused by loose wires and pins in the multi contact connector and the connectors look very similar if not identical.

Will see how it goes over the next few days. If all else fails, she will have to go in to Rigby Volvo.

Cheers,
Richard.

[Tatsfield]

Flexible conduits between the door and the frame can produce problems as the loom ages and the connectors corrode or the insulation on the wiring becomes brittle. It can be very hard to see wiring faults unless the cracks are big enough to see or the corrosion is extreme. It's always worth inspection the flexibble loom if you experience any fault in door mounted equipment.

[Cubbington]

Thanks both richardt1994 and Tatsfield for the input.

I managed to get a new lock mechanism ordered from my local Volvo dealer late yesterday afternoon and it arrived this morning!

So I’ve spent most of the day figuring out how to take the door apart to change the lock over, and the fault’s still showing...hacked off.com!

I had pretty high hopes that it was going to cure the fault, as there was water on the old lock, and the new one has a foam gasket above the latch, along with a big rubber boot, which covers most of the entire mechanism - I guess Volvo realised there was a water related issue with the original locks!

I took a couple of pics of both locks, so will post them up when I can figure it out again.

Anyway, I think you both may be on to something, as the door’s internal wiring loom which comes from the connector block and then into the door was damp, and most of the foam insulation disintegrated when I touched it. I also noticed the slightest bit of bare wire (only one wire) where the loom had chafed against the door frame. I cleaned it all up and wrapped the exposed part of the loom in self-amalgamating tape to protect it. I know my way around a bit of cable, so pretty certain it’s OK, but I’m by no means ruling it out.

I think I’ll remove the connector tomorrow and give the contacts a clean, but not sure that’s going to cure it...

I've been doing a bit of Googling, and all sorts of suggestions come up, but one stood out that seems to make sense, and that the car’s memory has stored the fault and thinks the door is still open, as I also still can’t lock it with the remote, the internal switches, or by pushing the knob down - I’ve pulled the fuse for the drivers door control, locked it using the key, and locked the rest of the doors manually for the time being so I don’t have to keep disconnecting the battery until it’s fixed.

I’m going to try and find a dealer who can connect it to VIDA on Monday to at least put the memory theory to the test - I disconnected the passenger airbag switch once and that needed the warning light to be reset by the dealer!

On the plus side, at least the window moves more quietly and quickly now, as I cleaned it thoroughly, as well as the foam runners it sits in - it needs to be removed to get the lock out, as the inner panel has the window mechanism and lock mounting plate riveted to it...took me a while to figure out how to get that out!

Apologies, time was against me, so didn’t have time to take loads of pics and do a write-up, but happy to point anyone in the right direction if they need to attempt this.

Will let you know what the eventual solution is, but I’ve had enough for today and am going to the pub!

Cheers,

Nick

[Cubbington]

OK, found an independent today who was able to hook it up to VIDA and retrieve a whole raft of fault codes!

They cleared them, reset all the door modules, and only one fault repeatedly kept returning; the humidity sensor on the inside of the windscreen is showing as faulty, with auxiliary faults as mirrors & windscreen defrost not working, which is odd, as the last time I checked, they do work, and when pressing the screen defrost button, the climate control seems to do it's thing as expected.

Apparently the humidity sensor goes back to the driver's door module, so it seems plausible.

I can't afford to buy even more parts ad-hoc, and haven't got the time to mess about so have just booked it into Volvo as the local main dealer could get the car in tomorrow.

Will let you know what the outcome is.

Cheers,

Nick

[Cubbington]

Got an update yesterday, and it is the driver’s door wiring loom that’s shot.

They’re having to get one from Sweden, so won’t be in until next week due to the Bank Holiday...made sure I put my mileage expense claim yesterday, I’m going to need it to pay for this...

I’m away with work until Friday next week, so won’t be able to pick the car up until Saturday, so will report back once I do.

Cheers,

Nick

[green van man]

The problem with thin copper wires in rubber conduits between car and doors is work hardening and snapping of the cores. Visually they look fine but the cores inside the insulation have snapped and make intermittent contact giving rise to the sometimes working sometimes not symptoms.

Back in the distant past when I wired rally cars for a hobby the smallest cable I would use was 1mm square copper conductor, purly for its mechanical strength, of course these days the wires on modern cars are strands of cotton in comparison. The frequent flexing of using the door gives rise to these mechanical failures and the drivers door being the most used is usually the first to fail.

Paul.

[Tatsfield]

So can we take it that the loom fault is specifically in the conduit flexed length between the door and the frame as I suggested, or is it somewhere else in the loom? The reason I ask is that it's useful when a theory is substantiated as it reinforces the chances of it being right the next time a similar fault is reported.

On a previous car I owned, the advice was to completely renew the flexed length of cabling with a length specifically designed to cope with flexing and to secure it with connectors at each end so that it could be easily removed if the door had to come off. The original was a solid length from door lock to well inside the dash area of the car!