[durvient]

Hi Guys, yesterday my car's door automatically unlocked while car was in motion forcing me to lock it manually however the unlocking kept happening on infrequent intervals.

The frequency is associated with bad/bumpy roads, never on a smooth potholeless road.

This issue had happened only once, 3 months ago and never surfaced again until yesterday.

I have checked for error codes but there isn't any, scan with VCDS is pending until I return to my home.

I had reported this problem to the VW Service Center during annual servicing but the engineer didn't find anything wrong on the car. Anyone else faced this issue or know what might be wrong and how to fix it?

[shancz]

Sounds like a loose connection/contact in the central locking system or any of the door locks. Hope it didn't have a water ingress event.

VCDS might/might not be as effective as reproducing it with a ASC technician on board.

[GTO]

Used to happen on our C-Class whenever the car hit a really bad pothole at speed. Mercedes dealer said the sensor that unlocks all doors in case of a crash was getting triggered.

[durvient]

Scanned with VCDS again! Turns out ignition switch has gone bad and causing the issue. Trying to source the switch and find out how it goes.

The unlocking isn't happening anymore but another issue came up that the doors aren't unlocking automatically upon removing the keys which seems to be due to the faulty ignition switch

[shancz]

Originally Posted by durvient

Scanned with VCDS again! Turns out ignition switch has gone bad and causing the issue. Trying to source the switch and find out how it goes.

I expect the ignition switch to last the lifetime of the car and I haven't heard of any such failures but this could be the first.
I haven't used VCDS but would suggest to double check that the ignition switch error isn't the result of some other issue like a faulty/damaged sensor or its connecting wiring.

- Could it be due to a faulty/low battery keyfob ? Since the unlocking doesn't happen which could either be due to a faulty switch or a faulty keyfob.
- Have the car battery checked for proper voltage too, I have seen a lot of weird issues being traced down to a failing battery.

I would also like to suggest adding some info about your car in case someone else can be of help with more accurate info. Like car model/year, does is have push button start or not etc.

Keep us posted.

[durvient]

Originally Posted by shancz

I expect the ignition switch to last the lifetime of the car and I haven't heard of any such failures but this could be the first.
I haven't used VCDS but would suggest to double check that the ignition switch error isn't the result of some other issue like a faulty/damaged sensor or its connecting wiring.....

Keep us posted.

I too had the same doubt, presuming Ignition switch being the last thing to fail however after scanning for faults, I watched a couple of videos and many mentioned that a faulty ignition switch in VAG cars can cause random electrical issues. Also, learnt that ignition switch life-cycle is completely luck dependant, while it does not fail for lacs of KMs, it often fails within the 3 or 4 digit mileages as well.

The switch replacement is due on Tuesday, I will post an update once it's done.