Door Lock Buttons

[Woods22250]

My door lock buttons work Intermittent. When I drive and shut off the truck I push the lock button and nothing happens. The other buttons do not work either. I can use the remote or the Intelligent access door handle and it locks immediately. I have done some trouble shooting and this is what I found:

1. Door lock buttons work upon staring truck and voltage is above 13.0v.
2. Door locks stop working when vehicle is shut off and voltage drops below 12.8v.
3. PID in forscan shows fault each time the driver door is pushed.
4. Unplug BMS and they work.
5. I replaced the battery with a new one and it did not change anything.

So, I need the forum's help in diagnosing and what else to trouble shoot.

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[airline tech]

Did you do the BMS Reset? after the battery replacement.
The door locks tie into the battery saver, like the dome lights, when they dim and shut off.
This is a pull-down resistor; the door lock circuit functions the same.

So, either with a scan tool the manual way, (Brake Pedal Press- Method) reset the BMS and it should work.

 

[Woods22250]

I thought Ford would have done this so but was not sure. When I got home I reset the BMS system to make sure but nothing changed.

 

[airline tech]

what is the fault code you get when the button is pressed?

 

[Woods22250]

No code it just says "fault."

 

[airline tech]

Just to ensure, you are not having this:

Switch Inhibit Feature

The switch inhibit feature prevents unauthorized access to the vehicle from the door lock control switchs. The BCM disables the function of both door lock control switchs 20 seconds after the vehicle is electronically locked. If any of these switches are activated while they are inhibited, a chime sounds and a message is displayed in the message center to indicate the switches are inhibited. The BCM enables the function of these switches when the vehicle is electronically unlocked.

So, this is just some possibilities, and without a code, more just operational notes below.

So, if you were to open the door and try either Drivers or Passengers door lock switch, they do not work until you have the truck running? Correct
Or is it only the Drivers side, if only the driver's side, then I suspect a bad resistor, in the driver's door.
It is designed to pull down the voltage and when you apply the ground (via) the switch it should allow voltage through it- so either a bad ground or connection at the switch or the resistor is blocking the power to it.

So basically, the voltage is shut off to the switch, until it sees a ground from the switch when you start the truck - you now have voltage being applied to the circuit

You may try running a BCM self-test with Forscan, this will do a reset of the BCM, as the batt save ties into this - as this is the control that is pulling down the resistor as disconnecting the BMS sensor changes your testing results, a BCM - Self Test may reset this feature to enable the switch to pull the ground through the resistor.

I hope I am making sense, and maybe this is a better way - the circuit shuts down (batt save) until woken up - either by engine start or switch activation, so either the BCM is not allowing the switch activation or the resistor itself is blocking it not letting the power through it.

C5018 - Resistor

 

[Woods22250]

None of the 4 switches work. At least nit until voltage is above or around 13v. I'll go try the bcm self test now.

 

[Woods22250]

Self Test did not fix it. Here is a shot of what the PID looks like when I operate the switch.

 

[RangerBill]

Just to ensure, you are not having this:

Switch Inhibit Feature

The switch inhibit feature prevents unauthorized access to the vehicle from the door lock control switchs. The BCM disables the function of both door lock control switchs 20 seconds after the vehicle is electronically locked. If any of these switches are activated while they are inhibited, a chime sounds and a message is displayed in the message center to indicate the switches are inhibited. The BCM enables the function of these switches when the vehicle is electronically unlocked.

So, this is just some possibilities, and without a code, more just operational notes below.

So, if you were to open the door and try either Drivers or Passengers door lock switch, they do not work until you have the truck running? Correct
Or is it only the Drivers side, if only the driver's side, then I suspect a bad resistor, in the driver's door.
It is designed to pull down the voltage and when you apply the ground (via) the switch it should allow voltage through it- so either a bad ground or connection at the switch or the resistor is blocking the power to it.

So basically, the voltage is shut off to the switch, until it sees a ground from the switch when you start the truck - you now have voltage being applied to the circuit

You may try running a BCM self-test with Forscan, this will do a reset of the BCM, as the batt save ties into this - as this is the control that is pulling down the resistor as disconnecting the BMS sensor changes your testing results, a BCM - Self Test may reset this feature to enable the switch to pull the ground through the resistor.

I hope I am making sense, and maybe this is a better way - the circuit shuts down (batt save) until woken up - either by engine start or switch activation, so either the BCM is not allowing the switch activation or the resistor itself is blocking it not letting the power through it.

C5018 - Resistor

I am not following your logic. The resistor that you reference is a pull-up resistor to apply voltage to the door lock switch Lock LED when the door is locked, and in the case of the driver's door a voltage to the ABS module that the driver's door is locked. When the door latch switch is indicating that the door is unlocked, the voltage is shunted to ground (voltage is removed) by the door latch switch. It is merely providing a feedback voltage to the ABS module and the door switch locked LED. It does not power the door lock motor.

I am thinking, as I believed you referenced earlier, that the Battery Monitoring System needs to know that a new battery has been installed in the truck. (BMS reset performed).

 

[Ext1809]

I have a similar issue, passenger door lock unlock works, button on key works but driver side has never worked. I think I have a faulty switch

 

[airline tech]

I am not following your logic. The resistor that you reference is a pull-up resistor to apply voltage to the door lock switch Lock LED when the door is locked, and in the case of the driver's door a voltage to the ABS module that the driver's door is locked. When the door latch switch is indicating that the door is unlocked, the voltage is shunted to ground (voltage is removed) by the door latch switch. It is merely providing a feedback voltage to the ABS module and the door switch locked LED. It does not power the door lock motor.

I am thinking, as I believed you referenced earlier, that the Battery Monitoring System needs to know that a new battery has been installed in the truck. (BMS reset performed).

YES, somewhere in a D&O it stated that the Door Lock switch, was depowered when the Batt Save feature activated.
However, in looking at the diagrams AGAIN, yes that is true - BUT 1 circuit is for the background illum of the switch and the other is for the - Door Lock (Ind) light. This is what the resistors are for, the pull down of the illumination, which I THOUGHT included the switch power, which it does not, upon a deeper look at the diagrams.

So, scratch all the resistor tie ins for THIS issue.

So, I would do a BMS reset again as this is the only logical thing that could possibly be dropping power from the BCM.

You may try pulling these 2 fuses for 5 minutes, these feed the Lock/Unlock Relays as well as the Micro-Relay (Input controller)
BCM Fuse 3 & 24

You can also try, using the key blade in the Dr. Door handle, to operate the locks from another source to see if that will reset the circuit.

There are also some - selectable options in the IPC Menu, - Switch Inhibit, Auto-Lock, Mis-Lock Etc
Try cycling those options - On & Off

other than this is splitting the system up and locating the bad connection or switch that is taking the circuit down (after shutdown)

 

[Woods22250]

I ordered a door switch yesterday from Ford. Arrives tomorrow, but in the meantime I will try the bms reset again along with pulling suggested fuses.

 

[Ext1809]

I ordered a door switch yesterday from Ford. Arrives tomorrow, but in the meantime I will try the bms reset again along with pulling suggested fuses.

Do you remember your part no.? I have looked but cannot find instructions on getting the door panel off, or if the switch is capable of being extended out. I am assuming there is a plug in the back.

 

[Woods22250]

See attached screenshot.

 

[Ext1809]

See attached screenshot.

~tip of the hat to you. Appreciated

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