peri77

OK disabling door control module makes sense, but it cannot disable the proximity sensor itself.

the_duke

How about you come up with some information supporting your position? I'm not just guessing here. I've had personal experience with the BCM disabling the door proximity sensors. You either have to lift the door handle to wake it up or unlock via the key fob. Replacing the battery solved the problem and all proximity sensors worked as normal afterwords. The information I posted was the best I could find. Unfortunately it isn't very clear exactly what it does at what stage. I would think "Entry and start authorisation control unit J518" might also cover the behavior.

Jack88

I'm inclined to agree with the Duke, even without the report. A failing battery leaves the car in a reduced power usage state, anything unnecessary to start the car is shut down. Most of the time the system does a good job, and you don't really notice much until it goes nearly all the way gone. You can take the battery out of the car and have an Autozone or some place similar load test it. That will give you a definitive answer if you don't have access to VCDS, at least about the battery. Do a search on battery replacement, usually VCDS is required to tell the car you've got a new one, but some people seem to have gotten away without doing that but I'm not sure how much of a pain it can be. I know it can cause at least temporary problems.

MP4.2+6.0

Keyless entry definitely gets cut with power management module. Had it happen a number of times, first person. Always maintained my keyless entry and soft close too, so everything handle related always worked. When I left lights on all day, it cut both keyless entry AND the remote control (cut later on/at lower power) to where on its last legs of life, I had to use key to open it and to start it. Also lost it a few times as battery was dying and other various overly exuberant VCDS and other draining. Whether it is cutting at module or at sensor I don't know, but function was cut.

If you suspect door handle itself, rather than boil the ocean on who's right, very simple to figure out. Unless all handles are toast, just try others. If behavior consistent, it's a power management power cut. If only one handle, a handle (sensor) related (mal)function.

97urS6

A couple of simple things to check... the battery in your remote might be low, I found mine was just marginal and I needed to be very close to the door for the proximity sensor to pick it up.
The other more likely issue is what I found inside your door ... a broken wire that powers your sensor, especially if other functions in the door are working?
But again it might be a failure in the door handle sensor... in that case you can find relatively cheap used door handles on eBay, some might even have the matching colour for the exterior door handle!

The.aviator2

I know my driver door proximity sensor was working when I first bought the car. Some time along the way it stopped and I noticed rear left door sensor stopped working as well. The feature still works on passenger and rear right doors. This is how I know it's not the battery module.

No fault code is given for those faulty proximity sensors. At least, I have nothing showing up in my scan.

Jack88

Well, if you have some working, some not, that would indicate it's the sensor in the door itself. It's either not recognizing you are there with the key or the handle itself is faulty. I'm not sure if the sensor that looks for the key is part of the handle or not, I'm sure MP4.2 knows.

Turbo Tony

Just to throw my two cents in, my experience is the same The Dukes - when the battery gets a little low, the doors won't unlock immediately on touching the handle, but wait until after the handle has been raised, which seems to wake up the system.

97urS6

Based on visual observation of the door handle mechanism itself, there appears to be a secondary connect type sensor that activates the unlock function when the door handle is raised. So this is how if the proximity sensor did not work, then lifting the door handle once will unlock the door.

hughmungus

Good write up, I have tried to do the same but couldn't figure out how to take the big aluminium door panel off. I took out around 10 screws but it just wouldn't come away at the top. Are there any special fixings other than screws ?