The door lock assembly module uses an electronic solenoid to unlock the door. The most common problem is failure of the microswitch or circuit board inside. This results in failure of the door to know when the door has been opened or closed. The door either thinks it's open or closed all the time since the switch no longer senses it. This can cause problems with the door locking by themselves or the alarm going off.
A broken wire at the door hinge (under the rubber accordian-like boot) can cause door problems as well.
To isolate a problem, here is a test for the most common failure - the driver's side door microswitch. Set the overhead light to turn on when the door is opened. Open the passenger side door - the light should turn on. Shut the door - the light should go off after a while. The driver's side door should do the same thing. Also compare to the rear doors.
Another test you can do is, with the doors locked, unlock the doors using the remote. Do not open the door. The doors should relock themselves in 30 seconds. This is a feature to prevent accidental unlocking. Now do the same test but open the door. If the door module switches are working correctly, the doors should not relock themselves.
8mm triple square bit
T-25 and T-20 torx screwdriver
all door handles: 3b0 837 207 g gru
front left module: 3b1 837 015 as (Jetta/Golf and 2000 and later Passat)
front left module: 3b1 837 015 an (Golf with manual locks, no power locks)
front left module: 3b1 837 015 e or 3b0 837 069 b (1998-2000 Passat)
front right module: 3b1 837 016 bh (Jetta/Golf)
front right module: 3b1 837 016 br (Golf with manual locks, no power locks)
front right module: 3b1 837 016 e or 3b0 837 070 b (1998-2000 Passat)
front right module: 3b1 837 016 cf (2000 and later Passat)
rear left module: 3b4 829 015 am (Jetta)
rear left module: 3b4 829 015 (Golf with manual locks, no power locks)
rear left module: 3b4 839 015 b or 3b4 839 015 ae (earlier and 2000 Passat)
rear left module: 3b4 839 015 am (2000 and later Passat)
rear right module: 3b4 829 016 ae (Jetta)
rear right module: 3b4 829 016 (Golf with manual locks, no power locks)
rear right module: 3b4 839 016 ae or 3b4 839 016 b (1998-2000 Passat)
rear right module: 3b4 839 016 am (2000 and later Passat)
Punch out the center of the 2x plastic plugs indicated by the yellow arrows
below. I don't know if you have to punch them out all the way but once the
inner metal door skin is loose you can retrieve them. Also push in
the rubber seal where the inside door latch cable passes through the inner metal
door skin and the door plunger (yellow arrows).
Below is a picture without the door skin for illustration.
Remove the 10mm bolts holding the inner metal door skin to the door. You can't remove it since the window regulator is still attached to
the window, you only need to pull it away from the door enough to unplug the wire
plug on the lock module. Remove the plug on the lock module,
indicated with yellow arrow below.
Remove the plastic plug covering the T-20 torx screw indicated below and unscrew
the T-20 torx screw as far as possible. You can remove the 2x 8mm triple square
bolts holding the door module to the door frame now or later. They are not
torx bolts, don't use a torx bit on them! The
third one without an arrow doesn't need to be removed unless you want to remove
You can now pry out the driver's side lock cylinder or pass side cover.
This unlocks the handle cable. Once the lock cylinder or cover is off, open the door handle and pry
out the cable.
Here is another picture with the handle cable halfway off for illustration,
outlined in yellow below.
The door module can now be removed. During installation, add medium strength threadlocker on the triple square bolts. Push the plastic rivets holding the door module in from behind. Also make sure the weatherstripping around the inner metal door skin is seated properly.
If you want to remove the door handle, remove the third triple square bolt. The handle should pull back and out. During installation, add medium strength threadlocker on the triple square bolt. Note the little flexible flap on the forward side of the handle - it should be inside the door during installation.
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