In case anyone has this happen to them (may be Navigator-specific), here's the story:
vehicle:
2016 Navigator
symptoms:
- power liftgate would open upon startup and would occasionally open on its own when the vehicle was left unlocked
- it would open 80% of the time but eventually was 99+%
- symptom would happen in the winter only (started last winter, went away in the spring, returned this winter). By winter, I mean lots of snow and sub zero temps and exposure to lots of moisture
- the liftgate initialization procedure did not fix it (I thought it had and said so in a different thread -- will have to update that)
- relevant body code:
===DTC B12E8:11===
Code: B12E8 - Liftgate/Tailgate Control/Release Switch
Additional Fault Symptom:
- Circuit Short To Ground
Module: Body Control Module===END DTC B12E8:11===
problem:
- there are 3 liftgate switches on the Navigator: one on the dash, one on the rear quarter panel, and one located in the liftgate molding (which also houses the license plate bulbs, backup camera, and liftgate glass switch); not sure if the Expedition also has an switch on the vehicle exterior
- they all seemed to be working ok
- the liftgate molding switch is somewhat exposed to elements since the molding is not designed to be a waterproof seal to the liftgate
- end result is corrosion formed on one of the connector pins and internal to the switch itself (see pics)
solution:
- the internal switch wire within the switch housing was so badly corroded, it did not withstand cleaning, so had to replace the switch
- p/n 1L2Z-014018-AC (alternate p/n SW5855)
- to remove the molding to gain access to the switch, you have to remove the interior liftgate trim pieces, 6 nuts, and release some push pins
other stuff:
- I would recommend using some kind of moisture repellant on the molding wiring and connectors and also internal to the switch housing itself where the terminal is exposed
- the liftgate glass uses the exact same switch but is located ~8in away; aside from rusted screws on the switch housing it was in excelelnt condition
Problem solved.



vehicle:
2016 Navigator
symptoms:
- power liftgate would open upon startup and would occasionally open on its own when the vehicle was left unlocked
- it would open 80% of the time but eventually was 99+%
- symptom would happen in the winter only (started last winter, went away in the spring, returned this winter). By winter, I mean lots of snow and sub zero temps and exposure to lots of moisture
- the liftgate initialization procedure did not fix it (I thought it had and said so in a different thread -- will have to update that)
- relevant body code:
===DTC B12E8:11===
Code: B12E8 - Liftgate/Tailgate Control/Release Switch
Additional Fault Symptom:
- Circuit Short To Ground
Module: Body Control Module===END DTC B12E8:11===
problem:
- there are 3 liftgate switches on the Navigator: one on the dash, one on the rear quarter panel, and one located in the liftgate molding (which also houses the license plate bulbs, backup camera, and liftgate glass switch); not sure if the Expedition also has an switch on the vehicle exterior
- they all seemed to be working ok
- the liftgate molding switch is somewhat exposed to elements since the molding is not designed to be a waterproof seal to the liftgate
- end result is corrosion formed on one of the connector pins and internal to the switch itself (see pics)
solution:
- the internal switch wire within the switch housing was so badly corroded, it did not withstand cleaning, so had to replace the switch
- p/n 1L2Z-014018-AC (alternate p/n SW5855)
- to remove the molding to gain access to the switch, you have to remove the interior liftgate trim pieces, 6 nuts, and release some push pins
other stuff:
- I would recommend using some kind of moisture repellant on the molding wiring and connectors and also internal to the switch housing itself where the terminal is exposed
- the liftgate glass uses the exact same switch but is located ~8in away; aside from rusted screws on the switch housing it was in excelelnt condition
Problem solved.


