The rear door lock has been playing up, working only occasionally, so when it finally worked, I decided to change the lock mechanism as it's impossible if you can't get the door open. For my car the lock part for rear left door is an 81410-2L010. There seems to be a lot of variation so make sure you get the exact lock for your car by searching on
www.partsouq.com using the car VIN. I managed to find a used one on eBay, but there were only a couple available. There were a lot more available for any of the other doors.
I followed this video for replacing the lock. The one thing the guy didn't seem to do is unplug the wiring from the lock, and it is really awkward to unplug with the lock in situ. This is because the guide rail for the window glass is right in the way. Unbolting the rail to move it out of the way means you can get your finger in to press down on the latch to release the plug. I included a photo of what the plug looks like (latch arrowed).
Other than that, it was pretty easy. I was able to work on my drive, and for the few days before the replacement lock arrived the door had no lock and the glass was held up by tape. I held the door closed by a piece of rope inside, after pulling it tight from inside I exited the door on the other side so I was able to lock the car. Because the door didn't close very tight I placed a couple of layers of corrugated cardboard over the door microswitch to keep it pressed in. Otherwise, I suspect it would set the alarm off. If you can only park on the street, don't start the job unless you have the parts to do it all in a day so as to keep the vehicle secure.
How To Install Replace Rear Power Door Lock Actuator HYUNDAI I30 CW 1.6L CRDI 2010~2012 D4FB H A4CF2 - YouTube
