Open 2014 Liftgate from Inside?

[Don Ridley]

Oh, I see the wiring diagram is in this thread. 

[4DoorDriven]

On 2/2/2018 at 9:36 PM, Don Ridley said:

The latch and lock are both controlled by the body control module BCM. There is a motor in the latch that may be bad. The "lock" appears to be logic in the BCM that knows when to send voltage to the motor. You can check for voltage but you need the wiring diagram, pin outs and some electrical knowledge. Otherwise, try replacing the latch motor. If power is not getting to the motor, the switch on the lift gate may be bad (pushing the latch pulls the voltage to GND and the BCM responds). Hopefully the BCM is OK.

 

Let me know if you want the wiring diagram.

Thanks for the response Don Ridley.

 

So we couldn't figure it out, it was taken to local Ford dealer and they replaced the latch(and wiring harness) this past Friday. But the problem made an appearance again today. Hahaha oh well. Will bring up a possible bad BCM when we take it Back to dealer before a possible trade-in. 

Again thanks for your insight on this, very much appreciated. 

[venajeff]

On 1/30/2018 at 10:05 AM, 4DoorDriven said:

I can lock/unlock all the doors with the key fob but the rear liftgate remains locked. 

So I have the same problem with my transit. And now the problem is getting worse. The rear lift gate is opening up all on its own. When it happens, it does it right when the automatic door locks happen when you start driving the vehicle. My wife was driving it the other day and the rear door opened completely, very scary for her. I have talked with ford and the only other thing to try is replacing the BCU, but it is not guaranty that it will fix the problem, and it is very expensive. I have already tried replacing the door locking mechanism. 

[Don Ridley]

I don't know how the previously listed problem was resolved. But here are my thoughts:

 

The BCM will open the rear door latch when it sees a +12V signal go to 0V on one of the inputs. By pressing the door latch button you pull the 12V signal to GND. Since the problem appears to happen when all the doors lock, there is a possibility a brief current surge is pulling down the 12V  "open latch" signal due to an electrical problem in one of the other locks or maybe inside the BCM.  If this is the problem it can be measured on the proper pin going into the BCM. I would hope the dealer would attempt to capture this possible voltage drop if it exists (a good digital voltmeter can do this). But this will only confirm the BCM is responding to the input. The fix may still reside inside the BCM.  I would be more comfortable replacing the BCM if it could be shown the 12V signal never went to zero but the door was opened anyway.

 

Also, check the battery voltage, It should be 14V or higher for normal operation.

 

Good luck.

[john89john]

Would there be any way to bypass the bcm to install a button straight to the lock actuator? if im not wrong thats what makes you able to open the liftgate? mines stuck i dont know if my bcm is bad just a question.

[Don Ridley]

See the wiring diagram earlier in this discussion. Fuse F65 may be blown. You can measure voltages coming off the BCM to see if it is working. You should be able to install a separate switch but the door may open even when the doors are locked. There may be ways around this but fixing the signal from the BCM or the actuator is best.

[john89john]

I tested the f65 its good. pulled the fuse one side is reading 12.1v

 

Edited March 13, 2019 by john89john

[Don Ridley]

Look for a voltage change at the BCM input from the switch, then check for a corresponding change at the BCM output to the latch motor. The previous posts have all the drawings and connector pin outs.

[john89john]

I'll give it all a read thru and check with a friend whos a bit more knowledgeable in the electrical field.

if it happens the lock actuator is bad is there a way to remove and replace it while the doors shut? i took the panel off and see 3 torx but was thinking about it if its latched to the striker. may not be possible.

 

 

[Fifty150]

On 2/24/2017 at 1:50 PM, pws5068 said:

After some testing, I had success by jumping pin 7 to 2! Going to install the switch this weekend!

 

Try jumping pin 7 to 2, first.  With any luck, that should release your door.  If that works, you will know that everything from there, to the door, is good.  Take a good look at the below diagrams, and make sure that what you are looking at on your car matches what you are seeing on the diagrams.

 

On 2/18/2017 at 6:54 PM, DonShockley said:

This will be slightly different since it's from my 2015 TC wiring book instead of the 2016 provided by Don Ridley earlier. But here is a diagram of the equivalent connector in my 2015. Also, if you look closely at the connector, there is usually some numerical marking of the pins so you may be able to match the earlier schematic that way.

On 2/15/2017 at 7:55 AM, Don Ridley said:

Better image.

After closer review the door switch provides a GND connection to activate the relay that opens the door. It does not look like you can separately add a GND to the relay that would open the door regardless of the lock/unlock status.

 

 

[john89john]

Thanks will do some testing this week.

Edited March 16, 2019 by john89john

[john89john]

it appears on the c435 connector has no 12+v.

i took it to the dealer as i finaly found one that will take my 3rd party warranty.

took it to where i bought it but they said they only " think" its the latch but not positive itll fix it, either way lock actuator, wiring or bcm is covered.

Edited April 18, 2019 by john89john

[Chip]

I'm trying to install a switch on the inside of the lift gate of my '21, so I can open it from inside. I just want a switch on the inside of the door itself.

 

My black/red connector box looks the same as pws'.

 

The two Don's and OP (too hard to type pws-autocorrect doesn't like it) had to spend a lot of time figuring this thing out. But the solution is simple, correct? Install a switch between the wires using pin 7 & 10, and that's all, correct?

 

Don R notes a 5.7 volt power source (pin 7?). I'll confirm that's what I have, too. A question about that switch--triggering the momentary switch connects, momentarily, the wires at 7 & 10, correct. That breaks the logic state... then what happens? The BCM tells the latch to open? And what happens to the diverted power--does it just run to ground? That's not normally good, is it?

 

What does "jump pins" and install a "jumper" mean in the context of this thread?

[Chip]

I compared the black/red connector in my '21 to the schematic from Don S. I may not be reading the schematic correctly, but it appears I have no wire at pin 10. So, I'm in search of guidance on what wire opens the lift gate latch. 

[Don Ridley]

Pressing the switch on the tailgate sends a GND signal to the BCM to tell the BCM to open the tailgate. If your connectors are differnt from the 2016 wiring diagram you will have to do some testing to find the right wires. 

 

First, find the wire going to the BCM from the tailgate switch. Measure each wire with a voltmeter. Find the one that goes from 12V to 0V when the switch is pressed. 

Next, find a ground wire. Use the resistance setting on your voltmeter to measure 0 ohms between a metal ground point and the wire. If you are not sure of the proper ground wire then you can connect to any piece of metal on the tailgate for a ground.

 

Connect one terminal on your new switch to the GND point (or wire) and the other terminal to the BCM wire you found in the fist step. When you press the new switch the BCM wire should go from 12V to 0V and the tailgate latch should activate (tailgate has to be closed to activate).