Ford Excursion door switch workaround

ukiltmybrutha · Sep 28, 2023

Hi,

I have a 2002 Ford Excursion where the VSM (Vehicle Security Module) died. The basic resultant issues were:

1) No power door locks.
2) Door Ajar light.

The VSM is no longer made and no longer repaired (not by any place that I trust anyways).

If you buy a used VSM they are quite a bit of money and must be reprogrammed by the dealer for about $380 or so. Most dealers I called are of the mindset that I just get a new truck. Well no way, this truck is new to me and now I know why the last person got rid of it.

I reflowed the solder on the main connectors but to no avail.

So I did the next best thing. I went on Ebay and got myself a used one. To my delight (sort of) the used VSM worked with one major issue.

The door switches only turn the interior lights on when the front doors are open. Basically, the ECM I purchased used belonged to a truck.

Now on a smaller sedan I might be able to get by with the rear interior lights not working when the door is opened. However on a vehicle this big it is not too fun in the 2nd, 3rd, and cargo area to be opening doors with no resultant interior lights.

So I grabbed myself a wiring diagram and found that the main dimmer switch allows all of the interior lights to come on when a ground signal is received. That circuit then goes through the instrument cluster where there is an internal relay.

That gave me a bright idea. I have the pinouts for the VSM and know which pins/wires are connected to the VSM via the rear door switches. Real easy access!

The only issue that I have is that door switches send a ground signal when the door is shut. In that scenario, the interior lights come on when the rear doors are shut which is exactly opposite of what I want.

Is there anything simple that I can do to force a ground signal to the main dimmer switch? I don't want to do anything invasive since the door switches are a nightmare to access and want to leave what is working well alone.

A relay for each door switch? Would that work? Anything simpler?

Thanks for any ideas.

Diver300 · Feb 25, 2024

Kovansky said:
Hello guys,

I have some questions.

Reading information in this topic, I came across some links that the user "rjenkinsgb" placed, about the configuration files of Ford vehicles, and although it looks like CAN BUS data, it only shows a few Bits

I would like to know how to interpret the information that the URL "https://www.motorcraftservice.com/AsBuilt" shows you, taking into account that I only have the Speedometer of a 2018 Ford Edge and I do not have access to the ODBII port of the vehicles (Only the Odometer, check URL "https://www.electro-tech-online.com/threads/trying-to-spy-can-bus-in-ford-edge-2013.165647/" for more Info)

Currently I have a ford edge 2013 and already tried to scan the ODBII DATA and use this DATA from my actually vehicle to turn on and working the odo from 2018 but only working a little few things (This is because Ford changed the CAN messaging from the 2011-13 version to the 2015-18 version.)

Note: I still have some confusion with decimal IDs and hexadecimal IDs in CAAN BUS (Any recommendation that helps me improve this is welcome).

The information on the PDF is only diagnostic information. Diagnostic information is only sent when there is something that is requesting information from the car.

There is nothing on the PDF that is the normal running information needed to make the car work.

The data for most of the modules (labelled BCE modules) is in the form "Module - Address - Instructions"
The first line is 7A7-01-01 0050 8000 0080
The "7A7" is the module. Diagnostic information is sent with CAN IDs in the 0x700 to 0x7FF range. Each module has one diagnostic CAN ID which it responds to, and the module is often referred to by that CAN ID. There appear to be six modules on that list.

The modules' diagnostic CAN IDs change much less often than the normal CAN messages.

I don't know what the "-01-01" or the "0050 8000 0080" means.

I think that you need a log from a working 2018 car. There may be several CAN buses on a car of that age.

rjenkinsgb · Feb 25, 2024

Diver300 said:
The information on the PDF is only diagnostic information.

The "asbuilt" files are the vehicle module configuration settings, in the state they were when it left the factory.

Some parts have been thoroughly documented by other enthusiasts; eg. to add additional features which do not require hardware, such as auto locking if a door is not opened, or live tyre pressure display.

Also, some popular upgrades such as keyless access, active cruise control and other things that can be relatively easily done with salvage parts.

The ones for the SYNC3 display system and dashboard displays are also pretty well known.

eg. This is a bit of the config breakdown for that, just one data line; the -01-02 is the specific config word within that module:

1234 5678 9ABC
7DO - 01 - 02 XXXX XXXX XXXX

1: Branding of unit, Where Ford = 0, Lincoln = 8, C = Configurable splash screen
Keep branding as Ford unless the Lincoln theme is desired
so : 7DO - 01 - 02 0xxx xxxx xxxx

2: USB 2 enabled and Navigation Application
if upgrading to sync 3 USB 2 is not required and Navigation must be set to Common HMI for TSR in APIM = 2
so : 7DO - 01 - 02 x2xx xxxx xxxx (note this is set to "4" in SYNC 2 which is "OFF" in SYNC 3)

3: Transmission type and stop start vechicle multiple choices for this option:
so : 7DO - 01 - 02 xxXx xxxx xxxx
8 = Auto and non Start/stop
9 = Manual and non start/stop
A = Auto with Start/stop
B = Manual with Start/stop

4: Door keypad menu and Ambiant lighting active (Mondeos generally do not have Door keypad Active)
so : 7DO - 01 - 02 xxxX xxxx xxxx : 8 = without Ambiant light, A = with Ambiant light

5:Fuel Type where 0 = Petrol, 4 = Diesel, 8 = CNG, C = BEV
so : 7DO - 01 - 02 xxxx Xxxx xxxx

6:Surround sound and Nav repeater Format : If upgradeing nav needs to be in Motorolla Format
so : 7DO - 01 - 02 xxxx xXxx xxxx : 0 = With Surround sound, 3 = without surround sound

shokjok · Feb 29, 2024

ukiltmybrutha said:
The door switches only turn the interior lights on when the front doors are open. Basically, the ECM I purchased used belonged to a truck.

The only issue that I have is that door switches send a ground signal when the door is shut. In that scenario, the interior lights come on when the rear doors are shut which is exactly opposite of what I want.

Is there anything simple that I can do to force a ground signal to the main dimmer switch? I don't want to do anything invasive since the door switches are a nightmare to access and want to leave what is working well alone.

Can you add a pull-up resistor to the rear door switch input(s) on the ECM to keep the lights off when all doors are closed?

Ford Excursion door switch workaround

ukiltmybrutha

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Diver300

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rjenkinsgb

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shokjok

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Ford Excursion door switch workaround

ukiltmybrutha

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