Passive entry not working on driver's door

The passive entry on my driver's side door is not working. It's not a problem with the fob or the SKS because it works fine on the hatch and the passenger door. Also, the button works to lock the car, just the proximity sensor doesn't work.

I'm assuming I need to replace the door handle, but before I go through that hassle (since it will need to be painted to match and everything) I thought I'd see if anyone had other suggestions. I checked the electrical connector last night while I was replacing the door check and found no corrosion or anything so it doesn't appear to be that.

 

Well, good news and bad news. The good news is I don't need a new door handle. I swapped the passenger one to the driver side and it still doesn't work (and the one from the driver side works fine on the passenger side). The bad news is I still don't know what's wrong. I tried the active tests, but I couldn't tell if they were doing anything since you have to run them with the ignition on so you can't lock the doors anyway. I didn't get any errors from toggling the sensors on and off, so I guess that's good? I did confirm that techstream sees a signal from the passenger side when I trigger the sensor and it doesn't from the driver side, but that's no surprise.

It sounds like replacing the ECU is a pain and the wiring in the door is mostly hidden so I can't really trace that very well. Feeling like I may be out of luck.

 

No smartkey errors. A few seemingly harmless ones that are maybe caused by running the healthcheck with the ignition on but not in ready: U0123, U0124, U0126 from the ABS/VSC module, C1532 from power steering, and B1421 from AC. Note that I have no warning lights on for any of those systems when driving the car.

Is the door receiver part of the box under the switch panel that a lot of the wires connect to? And if so, could I temporarily swap in the one from the passenger side just to narrow it down? I was able to do something similar on another car where I had lock issues to make sure I was buying the right expensive replacement part.

 

Well, I think I got it. Found a corroded connector in the door and after cleaning it up the passive entry works!

I opened it up again last night and tried swapping the little black box that appears to be some sort of receiver or transmitter from the passenger side, and at first that seemed to have worked. Then after I started to button things back up it quit working again. This made think there must be a bad connection somewhere near that box and when I shifted its position it got messed up. As it turned out, it wasn't any of the connections to the box itself, but a plug that clips to the same bracket.

It wasn't particularly obvious to me that this plug was related to the lock system, so I guess my advice to anyone with a similar problem would be to check all the connectors, even if you don't think they're related to your problem.

 

Well, I was a bit premature calling this fixed. It worked for about two days and then quit again.

I reopened it tonight and discovered that the connector wasn't just corroded, it was broken. One of the pins broke off inside the female part of the connector. I suspect what was happening is that when I fiddled with it, the broken ends made enough contact to work for a little while.

I'm not sure how I'm going to fix this properly since the connector uses tiny pins that are smaller than anything I've been able to find so far, but in the meantime I pulled the pins out and directly connected them with a piece of wire (wrapped in electrical tape to prevent shorting). Seems to be working so far, but it's not exactly secure. I suppose I could leave it and fix it properly if/when the hack fails.

In any case, I'm hoping it will be good to go for at least the winter so I don't have to fumble in my pockets for the key fob when it's freezing out.

 

I could, but since the rest of the wires in that loom can be disconnected I was trying to avoid a permanent connection. It occurs to me that I don't necessarily have to put them back on the original connector though. I have some RC-style connectors from a completely unrelated project that I could probably solder onto the wires and make a non-permanent connection that way. It might not be "right", but I'm willing to bet it would work anyway.