Door Lock Buttons

[RangerBill]

Ok, with all that has been reported and that the OP is stating that if the BMS sensor is disconnected - it works normally. I am leaning towards a bad BMS sensor, false reporting the battery voltage the system is responding to that (false data) and shutting off the voltage supply.


Disconnect the BMS sensor:

Connector Side:

Ign (OFF) - Measure pin 2 to GRD (Red Wire) - should match battery voltage (Post to Post)
with a variance tolerance of (.5) volt.
This wire is a direct feed from the small connector on the positive (BMFL) (Item (B) and is not pictured but you will see the connector (down on the side)
So this is (+) input for the BMS sensor

Ign (ON) - Measure pin 1 to GRD (White Wire) - this is the LIN circuit for the BCM monitoring.

Pinpoint Test, just asks:
Is voltage GREATER than 10 Volts?
Yes- Repair the Circuit
No - Proceed to deeper wiring checks

So, my thought is that if you have good battery voltage on Pin 2 (test result) then the BMS sensor is not accurately reading the voltage.

The issue is at this point, with Forscan, it is hard to navigate the LIve data pids, meaning I am not 100% sure exactly where in the system the previous (pic) you posted. Where is that specific data coming from?
So, if we assume that the BCM is actually seeing 11.8 volts then this is the possible reason for the locks not working.

Either way, if you can get it to work with the BMS sensor disconnected and it does not with it plugged in, then we can confirm that the issue is within the BMS circuit.

But you may also want to check for security the connection feeding down to the High Current Junction Box, this feeds down to a box under the BJB which has the main BCM fuse
Item (C)

The OP states that his battery voltage measured with a voltmeter is 11.8 volts (same as Forscan is reporting), so I don't think the BMS sensor is misreporting voltage. When he starts the truck, the battery voltage rises to 14.2 volts. I believe that unplugging the BMS sensor is merely disabling all BMS functions, allowing the door locks to work with low battery voltage. With the BMS connected and functioning, it will not allow door lock switches to operate with such a low battery voltage.

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[RangerBill]

disagree. I have the same problem and already changed battery did the battery reset and still same problem

You reported a different problem than the OP. You state that the driver door lock switch doesn't work, but your passenger door lock switch works. With the OP, none of his lock switches work with low battery voltage.

 

[airline tech]

another question would be:
If you were to shut off the truck and not open any door, to just listen to the radio.
It should run for (10-Minutes) and then auto time out (Accessory Delay) Relay or shut off when you open the door.
I use this regularly - in the employee lot at work

If it won't go 10-minutes then either the BMS sensor is bad, or you have a true bad battery, I am leaning towards a bad sensor.

 

[airline tech]

The OP states that his battery voltage measured with a voltmeter is 11.8 volts (same as Forscan is reporting), so I don't think the BMS sensor is misreporting voltage. When he starts the truck, the battery voltage rises to 14.2 volts. I believe that unplugging the BMS sensor is merely disabling all BMS functions, allowing the door locks to work with low battery voltage. With the BMS connected and functioning, it will not allow door lock switches to operate with such a low battery voltage.

OK, I missed that (The Same) statement

 

[airline tech]

The OP states that his battery voltage measured with a voltmeter is 11.8 volts (same as Forscan is reporting), so I don't think the BMS sensor is misreporting voltage. When he starts the truck, the battery voltage rises to 14.2 volts. I believe that unplugging the BMS sensor is merely disabling all BMS functions, allowing the door locks to work with low battery voltage. With the BMS connected and functioning, it will not allow door lock switches to operate with such a low battery voltage.

Yes- I agree 100%

 

[Woods22250]

Mystery solved. Right rear door lock connector unplugged. Plugged In an works fine now. Must have been this way when I bought it and I never noticed it.

 

[RangerBill]

Mystery solved. Right rear door lock connector unplugged. Plugged In an works fine now. Must have been this way when I bought it and I never noticed it.

Are you referring to the right rear door lock switch or door latch? If it was the door latch connector, I would have thought that you would have been getting a door ajar message.

 

[Woods22250]

Door lock switch. I have never been in the back so I never noticed the switch never worked until I tried every door switch again.

Thanks to all for your help in my wild goose chase.

 

[RangerBill]

Door lock switch. I have never been in the back so I never noticed the switch never worked until I tried every door switch again.

Thanks to all for your help in my wild goose chase.

So, your door lock switches now work with a low battery (11.8 volts) now?

 

[airline tech]

Good Find

 

[RangerBill]

Door lock switch. I have never been in the back so I never noticed the switch never worked until I tried every door switch again.

Thanks to all for your help in my wild goose chase.

Looking at the electrical diagram for the rear door lock switches, I am not seeing how this would give the symptoms that were described.

 

[Woods22250]

Currently, I don't have 11.8v but have 12.6v since I ran it for a few minutes. But yes all buttons work like they should. I wonder if the fault I was getting from the driver door lock pid in forscan was possibly showing an intermittent ground?

 

[airline tech]

OK, I think the issue was not so much - Control of the locks, it was the - Batt Save feature unable to see the Feedback resistance of the RR switch (Indicator) this is why it worked with the truck running.
The BCM was not allowing switch activation due to it could not see all the switches when Batt Sav Feature (triggered)

As this is the only thing, I see that ties into the transition of power (running vs shutdown)

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