Join Date: Dec 2019
Location: Frankfort, Illinois
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Trunk release malfunction
My wife's 2014 MKZ Hybrid has experienced problems during cold weather. The main control console functions (sliders, on/off buttons, etc) stopped working, and the trunk release also stopped working. She said it all started just as she was turning into the driveway and the auto headlights came on.
The Lincoln/Ford dealer had the car for five days (including the weekend, when they did not work on it) and they could not get it to fail so error codes could be checked. The service writer did witness the problem herself when my wife dropped the car off, but that didn't matter if the tech could not get it to fail during his troubleshooting activities.
The trunk latch behaved exactly as you described. The only way to get stuff out was to drag it through the fold down rear seat or to crawl into the trunk use the internal emergency release. The button on the dash did not work, the button on the remote did not work, the key code on the pillar did not work!
What were the weather conditions when your system failed?
Did you have any control panel functions stop working, or was it only the trunk release?
This car has been in the shop for this problem twice, both times during very cold weather.
The previous occurrence ended up with the shop replacing the 12V battery under the hood. They claimed that the battery was causing the problem.
Today the battery is still OK but the problem is back again.
After bringing the car home yesterday, it is still working "normallly".
It will be interesting to see what triggers the next malfunction.
I suspect that this is related to a control system circuit board that has a "cold solder joint" (a condition where a circuit "opens" as the board heats up and thermal expansion comes into play) or perhaps a relay or other active component that misbehaves under certain thermal conditions, right after a high current draw (caused by the auto head lamps turning on). I doubt that there is an error code that will actually reveal this kind of problem, which means that this may never get resolved.
I look forward to hearing from you... if there are enough people out there who are having this issue, maybe the Lincoln engineering department will take notice and issue a factory notice advising their service departments how to properly troubleshoot the problem.