07 Explorer: What controls the door locks

[c_monster70]

I recently acquired an 07 explorer for my daughters high school career. Despite the 179,000 miles it's in excellent condition.

Concerning the door locks. In my experience Ford key fobs are click once to unlock the drivers door and twice for the rest. This vehicle unlocks all doors with a single button push. Sometimes pushing the lock button activates the unlock side of the system. Replaced the fob batteries and eventually the fobs, but that isn't the problem.

If that was the only issue I could live with it, but in addition, the locks also unlock themselves randomly. The dome lights and park lights come on like the fob was used, but it happens even if I lock it with the interior button and leave the fob at home. Sometimes its two seconds after the doors are locked, sometimes it's two hours, but they always unlock.

I've deactivated both the auto lock and auto unlock features. I can find no issues with fuses or wiring, so I can only conclude that whatever module that controls the door locks is malfunctioning. I need to know what module I need to acquire. I've read a hundred threads about GEMS, and VSM's, and PATS, etc etc. But nobody seems to be having quite the same issues.

Any help is appreciated.

 

[Bill MacLeod]

The power locks and windows are very complicated in these trucks. I have all the 06 shop manuals and wiring diagrams and after a quick review can offer the following info:
The transmitter (keyfob) can unlock all doors with either one press of the unlock button or 2 presses. To change position, press the lock and unlock buttons at the same time and hold for 4 seconds. The turn signal lamps flash to confirm the feature is toggled. ( the 1 press of the unlock button is called global unlock)
The smart junction box stores codes. As an example, B1300 is for power door lock circuit failure. There are numerous other possible codes.

Hope this info is of help.

 

[c_monster70]

It's a beginning. Thank you.

So this "smart junction box" spits out "B" codes. Does that mean the Smart junction box and body control module are the same thing? I can access the BCM with forscan, but I can't find the SJB.

 

[Bill MacLeod]

I don't see any reference to a Body Control Module. The SJB is a combination of a multifunction control module and an interior power junction box. The systems it controls are: illuminated entry and interior lamps, exterior lamps, horn, remote keyless entry system, power door locks, smart locks, warning chimes and windshield wipers.

So they "may" be the same thing. Do you have any B codes stored?

 

[Explorer_PL]

I had the door locks cycle and open every few minutes - that was years ago. After a snow or rain, it would just unlock itself out of nowhere. After months of trying to figure it out, I found a broken ground wire under the driver door seal. There is a harness going under the door trim that the guy who installed the remote starter and alarm tapped into. He spliced the lock wires and over time they corroded to the point that they were grounding with bad weather. The locks in those cars are always hot, when you press the door lock switches, you are grounding them. In my case that ground wire was touching the body of the car and closing the circuit. Check for aftermarket stuff in you car. Hope that helps.

 

[Bill MacLeod]

Timely post PL, I agree that the grounds need to be checked. Corrosion (green rot) has been a big problem with many Ford vehicles. The 2nd gens had issues with corrosion at a slice inside a conduit for the harness beside the drivers rear seat. Created similar issues for the door locks and I had this happen with my 99 EB.

To the OP, the main ground (G300) is located at the bottom of the left A pillar. Remove the interior kick panel beside the hood release. Should be 2 black wires to a ground screw. One goes directly to the "Master window adjust switch". The other goes into the main harness that PL mentions above. When the harness is opened, you will find a splice (S300) with about 4 other black wires. These are the ground wires for the SJB, drivers side door lock switch, rear view mirror switch, power seat switch, interior lights, vanity/map light, roof panel opening, etc.

This is where I would start.

 

[c_monster70]

I don't see any reference to a Body Control Module. The SJB is a combination of a multifunction control module and an interior power junction box. The systems it controls are: illuminated entry and interior lamps, exterior lamps, horn, remote keyless entry system, power door locks, smart locks, warning chimes and windshield wipers.

So they "may" be the same thing. Do you have any B codes stored?

Right... BCM was a different vehicle. Explorer doesn't have one. I did hard resets of the GEM and Instrument cluster .......but it seems my initial diagnosis may have been correct and Autozone just screwed me. After I disconnected the laptop from the truck Saturday the locks went a little crazy. With nothing else to check I pulled the battery out of the new FOB and it immediately stopped. So I ordered FOBs off Amazon. I'll program one when the kid gets home from practice tonight and see where I stand.

Oh, and the only B code stored is for the TPMS, which I was already aware of.

I appreciate the help. I'll keep you posted.