How to lock a VW without setting the alarm

1 Apr 2018

Lock passat.320x320

We are not the first to experience a problem with the boot sensor on our Volkswagen (the internet suggests). So I am posting this in the hope that it helps someone else in the future. Here is how to lock a modern VW without switching on/activating the “anti-theft alarm” (see near the end for step-by-step instructions).

We used to own a Golf, and its alarm started going off because it “thought” its boot - or trunk, if you prefer - was opened. In that car the problem was caused by a leak from the little tube that transports windscreen washer fluid to the rear window. Since the car is being told that the boot is opening and closing, it sets off the alarm. The local garage was closed but they suggested disconnecting the battery. This is harder than it sounds if you are away from home without any tools.

In our more modern Passat we had the same thing happen, for apparently different reasons. Driving along the motorway, the interior lights suddenly turned on. This feels like a slight inconvenience - accompanied by the “bing” of the warning system, it’s mildly distracting, especially when the boot apparently opens and closes itself a few times every minute.

Anyway, that’s fine. The problem comes when you park up for the night, and lock the car. Like with the old Golf, the boot sensor effectively flip-flops between open and closed, triggering the alarm. “Aha,” I thought, “this has happened before. I’ll disconnect the battery.” Not really possible without a spanner/wrench/correctly-sized socket, especially if your vehicle toolkit is under the boot floor, and your boot is full of the luggage of a four-person family, and the boot lid won’t open because you’ve disconnected the powered opening mechanism while trying to disable the sensor (see earlier).

So it was that I found myself in the car park of a motorway hotel at 9:30pm, trying every possible sequential combination of locking the car, fiddling with spare keys, unlocking manually, wondering if I could open a window and reach the door handle - all sorts of fun. This so that the other guests could catch some sleep without listening to our car alarm squawking all night.

Here are the results of 20 minutes of fiddling.

  1. Before starting, ignore (or reinterpret) what the manual says. Ours states “The anti-theft alarm is not activated when the vehicle is manually locked using the spare key”. This is horseradish of the highest order. Well, significant extra knowledge is required, anyway. Read on.
  2. Locate your spare key. For our Passat, it’s a plastic key “concealed” within the normal remote-control type vehicle key.
  3. Open the passenger door and remove the rubber seal from the end face of the door. There’s a little slot beneath it that the spare key fits into. That comes in handy in a minute. For now, keep the little rubber seal somewhere safe.
  4. Empty the car of passengers, and get into the front passenger seat.
  5. Close all the doors.
  6. Reach across, past the steering wheel, and press the lock button on the driver’s door - the lower one in the picture above, with a little key on it. It locks all the doors and the boot.
  7. From inside, open the passenger door.
  8. Use your spare key to turn the little slot on the end face of the passenger door.
  9. Close the door and confirm that all doors are locked and the little red LED is not flashing. In other words, that the alarm is not active.

Hope this wins you a good night’s sleep.

The fix for the boot sensor problem, for us at least, was giving the “catch” a bit of a clean with a damp cloth. A bit like blowing into a USB socket, it somehow seemed to get things working again. (No sign of water ingress or pipe burst in the modern Passat).

Tags: car