Ford Excursion door switch workaround

[ukiltmybrutha]

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]

You should share the circuit diagram here so we can see what you are working with.

Do the door switches connect to anything at all now that you have a VSM designed for a truck?

Relays are probably not a good idea as you would need one for each door, and they would probably end up being turned on the whole time that the doors are shut, so the current taken by the coils would be discharging the battery even if the lights are off.

One problem that you could have is that the switches may not work reliably with a really small current, and you can get leakage currents quite easily if there is moisture anywhere. As the switches are on when the doors are closed, they will take current when the car is left with the doors closed. Car manufacturers get around that by pulsing the current to the door switches. They would be using something like 10 mA or so, but only turning that on for perhaps 1 ms every 100 ms, so the average current is only 0.1 mA per door, which is fine, and the delay of 100 ms wouldn't be noticeable.

You could have a MOSFET for each door, and a compromise current of 1 mA which will probably work fine and won't add much to the current when the car is off. I can draw the circuit out if you want.

 

[rjenkinsgb]

Traditionally, door switches break the circuit when the door is closed - they generally used to switch the ground of the interior light.

Are you certain yours of the way yours operate?

For information:
You may be able to reprogram the VSM yourself.

Get a copy of "Forscan" here (it is free):

FORScan Home

plus an OBDII interface that's listed as compatible.

That allows you to do most of what a dealer can do, on Ford vehicles.

Then go here:

https://www.motorcraftservice.com/AsBuilt

Enter the vehicle VIN and it will provide the original configuration file, which includes every module in the vehicle.

You should be able to load that in to Forscan then select the VSM and write the correct config data to it.

If the truck is too old for the As-built database, you could ask on either the Forscan forum, a Ford forum or the MHH Auto forum, for anyone that has the same vehicle and see if they can provide the module parameters.

A typical module config file in Forscan backup format looks something like this, anything from a couple of lines for single function or simpler modules up to thirty or so for complex ones.

eg. This is a backup of my ABS module config file:

;Block 1
760G1G15746304558D3
760G1G25857504345F1
760G1G34752303537A0
760G1G43536D7
;Block 2
760G2G1263613231C18
760G2G297020004
;Block 3
760G3G155C0

If the module you have is the same main part number as the original and has the same connector pins populated, then I'd be pretty confident it can be made to work with just the correct config data.

 

[Diver300]

Traditionally, door switches break the circuit when the door is closed - they generally used to switch the ground of the interior light.

Are you certain yours of the way yours operate?

A lot of modern cars have door switches that short to ground when the door is closed. That is usually in the door latch nowadays.

It's been a long time since the interior light was only controlled by the door switches. The body control module or similar powers the interior lights, and the door switches are just inputs to that.

 

[ukiltmybrutha]

Wow, thanks so much for these posts!

I will be uploading diagrams shortly. I would like to remediate this either via a supplemental method or via the ForScan method. There was such little information out there on it though specific to the Excursion even though this issue is pretty common so I kind of backed off and went to thinking about a supplemental path. Either way I am fine.

Also, as to:

Do the door switches connect to anything at all now that you have a VSM designed for a truck?

Yes, the wires still connect to the VSM on the exact same pins as the old VSM.

If the module you have is the same main part number as the original and has the same connector pins populated, then I'd be pretty confident it can be made to work with just the correct config data.

The module is from a model that is one year newer than the one that I own. My Excursion is a 2002. The module that I obtained was from a 2003. I did this for a few reasons:

1) This problem appears to apply mostly to 2002 Excursions. I was hoping that a newer module didn't have hardware issues and wasn't as prone to failure. As a matter of fact, a 2004 VSM is cited to be the correct replacement but would still need to be reprogrammed.
2) There is a shortage of 2002 VSM(s)
3) There is a post of a guy saying that you can use a 2003 so long as everything else lines up.
4) The 2002 VSM is on average about $400 bucks on Ebay and could still require programming whereas I was about to get this for about 150 bucks.

New possible concerns about this approach

1) I called Auto ECM who claims to rebuild these (I hear that they just chance used ones and throw labels on them (but I can't be sure) https://www.autoecmstore.com/products/2c7t-15k602-aj. They advise that they are out of stock. I asked them about using the ECM and they advised that reprograming wouldn't work because the difference is in the hardware. That is a powerful statement and a bit concerning. There is some definitely some conflicting information out there.

2) It seems that Ford changed their Door switch configuration on the Excursion in 2004 from going to Ground when shut to going to ground when open. Presumably, I could go in there and change all the door switches but that is not fun and I still have to worry about the liftgate switches.

Just FYI, the original part number I pulled was:

2C7T-15K602-AJ

The one that I now have is:

3C7T-15K602-AE

Supporting post for this (well showing that it is possible for it to work anyways) but still questionable since we don't know what the guy got back....could have just been a 2C7T-15K602-AJ VSM in another case....or maybe they reprogrammed it for him?

https://www.ford-trucks.com/forums/1...lock-saga.html <-----------(Post number 9)

Thanks so much and diagrams coming next.

 

[rjenkinsgb]

A lot of modern cars have door switches that short to ground when the door is closed. That is usually in the door latch nowadays.

The OPs vehicle is 2002, so not all that recent?

The only door switch I've had direct experience with recently was on a 2008 Grand Vitara, and those are definitely press-to-break - I have a spare here & just verified that.

>google< out of curiosit -
And, I've found the full wiring diagram manual for the 2002 Excursion near the top of this page - but the present Acrobat reader has removed the page rotate function & it's giving me a pain in the neck trying to follow it!!

Full wiring diagram for all 2002-2003 F series and excursions. - Ford Truck Enthusiasts Forums

1999 to 2016 Super Duty - Full wiring diagram for all 2002-2003 F series and excursions. - After searching the whole internet for a solution to my no crank no start issue with my 2002 f250. I came across a very helpful site and was able to obtain a full wiring diagram for my truck. I dont know...

www.ford-trucks.com

 

[ukiltmybrutha]

Please see attached. I will continue to add if necessary. On attachment "184" please see pins 11/6/12 specifically for rear door switches.

For attachment "73" please see pin 2 of the dimmer that I can tap into and give a ground to get all of my interior lights to come on.

 

[Diver300]

Do the door switches connect to anything at all now that you have a VSM designed for a truck?

Yes, the wires still connect to the VSM on the exact same pins as the old VSM.

Ok, but do they have any function?

The VSMs for cars and trucks will basically be the same item. Ford would never change the connector sizes between the vehicle types, as there would be virtually no saving in re-engineering a module for trucks. Trucks will probably have no wire going to those pins.

The truck VSMs may have missing components inside, or it could be a software change.

I wanted to know if the wires from the door switches go anywhere else as well as the VSM, or if the truck VSM has any reaction to the rear door signal.

 

[rjenkinsgb]

Just FYI, the original part number I pulled was:

2C7T-15K602-AJ

The one that I now have is:

3C7T-15K602-AE

I believe the last two characters are the factory settings or firmware to match a specific model of vehicle.

The first character being different is a bit worrying though; that (to my limited understanding) denotes a different vehicle model. I have no idea if that matters or not.

Searching shows the first to be a 2002 - 2007 F250/350/Excursion, while the second one comes up as a 2003 "Super Duty Excursion", whatever that is??

 

[ukiltmybrutha]

The OPs vehicle is 2002, so not all that recent?

The only door switch I've had direct experience with recently was on a 2008 Grand Vitara, and those are definitely press-to-break - I have a spare here & just verified that.

>google< out of curiosit -
And, I've found the full wiring diagram manual for the 2002 Excursion near the top of this page - but the present Acrobat reader has removed the page rotate function & it's giving me a pain in the neck trying to follow it!!

Full wiring diagram for all 2002-2003 F series and excursions. - Ford Truck Enthusiasts Forums

1999 to 2016 Super Duty - Full wiring diagram for all 2002-2003 F series and excursions. - After searching the whole internet for a solution to my no crank no start issue with my 2002 f250. I came across a very helpful site and was able to obtain a full wiring diagram for my truck. I dont know...

www.ford-trucks.com

Yes, I have that wiring diagram and thanks. I am printing to .pdf for the appropriate pages and attaching them. I can't find the 03 anywhere which might be nice in this case but might not be relevant.

 

[Diver300]

The OPs vehicle is 2002, so not all that recent?

The only door switch I've had direct experience with recently was on a 2008 Grand Vitara, and those are definitely press-to-break - I have a spare here & just verified that.

Just because a 2008 Suzuki has an "old" arrangement, does not mean that a 2003 Ford will also have an "old" arrangement.

I had a 1984 car (Austin Montego) with electronically controlled windows, so it had the driver's window with one-touch and auto-cut out.

Move on 20 years, and the car my daughter later owned, a Nissan Micra, was built. It had electronically controlled fuel injection, electronic throttle, fuel computer and keyless entry. You might expect all the electrics to be more modern than on the 1984 car, but no, the electric windows on the Micra were controlled with just switches, nothing else. The supply current and the earth current for the passenger window had to be routed though the driver's door.

The circuit diagram that the OP posted of a 2002 F250 shows the two liftgate switches in series. I would assume that Ford want to tell the customer if the liftgate isn't properly closed on either side, so the fact that they are in series would imply that the switches are closed when the liftgate is closed. It would be very odd for the door catches and the liftgate catches on one car to work opposite way round.

 

[rjenkinsgb]

I found the original part number on ebay, from a 2003, with a seller that listed the VIN - so I could grab the as-built data from that specific vehicle. It shows the data does go back to those.

It also has specific instructions for VSM installation:
(Edit- wrong image initially..)

 

[ukiltmybrutha]

I believe the last two characters are the factory settings or firmware to match a specific model of vehicle.

The first character being different is a bit worrying though; that (to my limited understanding) denotes a different vehicle model. I have no idea if that matters or not.

Searching shows the first to be a 2002 - 2007 F250/350/Excursion, while the second one comes up as a 2003 "Super Duty Excursion", whatever that is??

I used to be a Ford Car Stereo bench tech back in the 90's not saying that I am or was ever great with electronics either. I was young and not a Jedi yet.

However, I do recall one thing clearly but not sure if anything has changed.

The AJ works/worked like this. The A part is what needs/needed to match. The J represented how many times Ford revised the part.

 

[ukiltmybrutha]

I found the original part number on ebay, from a 2003, with a seller that listed the VIN - so I could gram the as-built data from that specific vehicle. It shows the data does go back to those.

It also has specific instructions for VSM installation:

I wonder if the one I have has the VIN, let me check. Thanks for that! EDIT: No such luck on this one.

 

[rjenkinsgb]

I wonder if the one I have has the VIN, let me check. Thanks for that!

It's the VIN for YOUR vehicle that matters, as that's how you get the correct module config?

 

[ukiltmybrutha]

It's the VIN for YOUR vehicle that matters, as that's how you get the correct module config?

I sent you a private message. Not to derail this thread, keep anyone out of the loop or inhibit meeting of the minds. Just to reduce exposure of VIN etc. I hope you don't mind.

 

[rjenkinsgb]

I've just looked at the asbuilt file I downloaded - it's tiny, the entire content are also visible in the screenshot - I thought that was just an overview!

The config for the VSM is just the one line, with three, four-character blocks.

 

[rjenkinsgb]

I sent you a private message. Not to derail this thread, keep anyone out of the loop or inhibit meeting of the minds. Just to reduce exposure of VIN etc. I hope you don't mind.

No problem, but I was meaning for you to look up your vehicle VIN on the motorcraft site, to get the file & data you need?

 

[ukiltmybrutha]

No problem, but I was meaning for you to look up your vehicle VIN on the motorcraft site, to get the file & data you need?

Where do I go to do that? EDIT: Sorry, I missed that in your above post. I downloaded the AS-Built info successfully. Thanks again.

I have issues with ADHD so your patience is appreciated.

I purchased one of these from Amazon. Delivered today out in a rural area! I have never had anything delivered "same day". Awesome.

I hope this process isn't too hard. I heard from someone that the instrument cluster might even need to be reprogrammed.

 

[shortbus=]

he VSMs for cars and trucks will basically be the same item. Ford would never change the connector sizes between the vehicle types, as there would be virtually no saving in re-engineering a module for trucks. Trucks will probably have no wire going to those pins.

Not trying to derail the thread, but Ford does some pretty dumb things. A motor or transmission from a Mustang, will not interchange with the same size motor in the same year truck. I got stuck after buying a Mustang motor to put in a truck. haven't messed with Fords since.

Back to the regular thread topic.