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.

 

[ukiltmybrutha]

Got the cable and ForScan. I cannot see any location which allows modification of the VSM unfortunately.

 

[ukiltmybrutha]

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.

Would you mind drawing this circuit please? Thanks.

 

[rjenkinsgb]

Got the cable and ForScan. I cannot see any location which allows modification of the VSM unfortunately.

Once you have clicked the Forscan connect button & the connection has finished setting up, go to Configuration and Programming - the diagonal IC symbol.

That should show a list of accessible modules in the vehicle - what do you get in there??

You could do a backup of the vehicle as is, if you follow this -

How to Use FORScan to Backup Module Data File - Auto Repair Technician Home

Before you use FORScan to program modules,you would better to backup your vehicle’s modules original data file in case you make modules dead.Here is a [...]

www.car-auto-repair.com

That uses the same functions pages, to read all the accessible module.

The VSM settings could be part of the BCM data, from looking at the file I grabbed??

 

[Diver300]

Would you mind drawing this circuit please? Thanks.

When the door is closed, the switch will closed, so there is no voltage on the MOSFET gate so it is turned off.

When the door is open, the switch is open and the supply voltage will be applied to the MOSFET gate via the 10 kOhm resistor, so the MOSFET will turn on and the dome lamp will come on.

There will be around 1 mA flowing though the 10 kOhm resistor all the time that the car is not being used.

Depending on how the rest of the car works, there could be issues with this.

The VSM is only looking at the front doors. If the supply to the dome lamp turns off when the front doors haven't been opened for a while, then opening the back doors won't bring the light on.

If the VSM (or whatever powers the dome light) detects that the dome light is on when it didn't turn it on, then you could find that it will refuse to turn the light on after that.

 

[ukiltmybrutha]

Once you have clicked the Forscan connect button & the connection has finished setting up, go to Configuration and Programming - the diagonal IC symbol.

That should show a list of accessible modules in the vehicle - what do you get in there??

You could do a backup of the vehicle as is, if you follow this -

How to Use FORScan to Backup Module Data File - Auto Repair Technician Home

Before you use FORScan to program modules,you would better to backup your vehicle’s modules original data file in case you make modules dead.Here is a [...]

www.car-auto-repair.com

That uses the same functions pages, to read all the accessible module.

The VSM settings could be part of the BCM data, from looking at the file I grabbed??

Once you have clicked the Forscan connect button & the connection has finished setting up, go to Configuration and Programming - the diagonal IC symbol.

That should show a list of accessible modules in the vehicle - what do you get in there??

You could do a backup of the vehicle as is, if you follow this -

How to Use FORScan to Backup Module Data File - Auto Repair Technician Home

Before you use FORScan to program modules,you would better to backup your vehicle’s modules original data file in case you make modules dead.Here is a [...]

www.car-auto-repair.com

That uses the same functions pages, to read all the accessible module.

The VSM settings could be part of the BCM data, from looking at the file I grabbed??

 

[ukiltmybrutha]

View attachment 142902
When the door is closed, the switch will closed, so there is no voltage on the MOSFET gate so it is turned off.

When the door is open, the switch is open and the supply voltage will be applied to the MOSFET gate via the 10 kOhm resistor, so the MOSFET will turn on and the dome lamp will come on.

There will be around 1 mA flowing though the 10 kOhm resistor all the time that the car is not being used.

Depending on how the rest of the car works, there could be issues with this.

The VSM is only looking at the front doors. If the supply to the dome lamp turns off when the front doors haven't been opened for a while, then opening the back doors won't bring the light on.

If the VSM (or whatever powers the dome light) detects that the dome light is on when it didn't turn it on, then you could find that it will refuse to turn the light on after that.

I will have to look further into the circuit but this is great! Thanks!

 

[ukiltmybrutha]

Once you have clicked the Forscan connect button & the connection has finished setting up, go to Configuration and Programming - the diagonal IC symbol.

That should show a list of accessible modules in the vehicle - what do you get in there??

You could do a backup of the vehicle as is, if you follow this -

How to Use FORScan to Backup Module Data File - Auto Repair Technician Home

Before you use FORScan to program modules,you would better to backup your vehicle’s modules original data file in case you make modules dead.Here is a [...]

www.car-auto-repair.com

That uses the same functions pages, to read all the accessible module.

The VSM settings could be part of the BCM data, from looking at the file I grabbed??

Let me think this through, read this link and perhaps try it out. Thanks....I provided a picture of what the IC symbol provides.

 

[shortbus=]

Do you have the pin outs for both controllers? Some times the same connectors are used but the wire positions change in the connector.

For example I had a Chevy Silverado the the BCM went bad in it. Got one from the junk yard from a truck one year newer. When I put every thing back together(and never tried it, I was sure everything would be OK) the module that was put in had 2 wires switched. Instead of the drivers door shutting the retained power off it now had the passenger door doing that task.

So you should com the wiring schematic of the original against the replacement.

 

[ukiltmybrutha]

Do you have the pin outs for both controllers? Some times the same connectors are used but the wire positions change in the connector.

For example I had a Chevy Silverado the the BCM went bad in it. Got one from the junk yard from a truck one year newer. When I put every thing back together(and never tried it, I was sure everything would be OK) the module that was put in had 2 wires switched. Instead of the drivers door shutting the retained power off it now had the passenger door doing that task.

So you should com the wiring schematic of the original against the replacement.

I think that I checked into that. Can't remember honestly. I don't have the pinouts for the 03 in front of me. If I had the pinouts for the 03/04 it would be helpful but for some reason the 02 is the one that frequents the internet.

 

[rjenkinsgb]

Let me think this through, read this link and perhaps try it out. Thanks....I provided a picture of what the IC symbol provides.

From the wiring diagram, the diagnostic connector has three different bus connections.

It looks like Forscan is only reading the bus on pin 7 (ISO), from what connects to that on diagram? That one includes restraints, ABS, Parking aid module, 4WD control etc.

There is a two-wire bus SCP (CAN?) on pins 2 & 10 which connects to the PCM and instrument cluster etc.,
and then another bus on Pin 3 (UBP), which has the VSM, EATC, another link to the cluster and the drivers seat?

OK, it is talking to the PCM, as it's detected a trouble code in it.


The DTCs are: U1262 in instrument cluster SCP bus fault (the two wire one).
P0603 PCM keep-alive memory (Possibly from having the battery disconnected???)
P0500 Speed sensor malfunction
P1812 4WD mode switch fault
P1832 TCM pressure control

The instrument cluster may? provide a gateway from the SCP bus to the UBP bus, if there was no fault??

 

[ukiltmybrutha]

From the wiring diagram, the diagnostic connector has three different bus connections.

It looks like Forscan is only reading the bus on pin 7 (ISO), from what connects to that on diagram? That one includes restraints, ABS, Parking aid module, 4WD control etc.

There is a two-wire bus SCP (CAN?) on pins 2 & 10 which connects to the PCM and instrument cluster etc.,
and then another bus on Pin 3 (UBP), which has the VSM, EATC, another link to the cluster and the drivers seat?

OK, it is talking to the PCM, as it's detected a trouble code in it.


The DTCs are: U1262 in instrument cluster SCP bus fault (the two wire one).
P0603 PCM keep-alive memory (Possibly from having the battery disconnected???)
P0500 Speed sensor malfunction
P1812 4WD mode switch fault
P1832 TCM pressure control

The instrument cluster may? provide a gateway from the SCP bus to the UBP bus, if there was no fault??

Perhaps. The dash was taken down to get to the VSM. I will reconnect everything to see if I can reduce the amount of false codes. Thanks.

 

[ukiltmybrutha]

I could only reduce down to 3 codes. Not sure if any of these would be preclusive to providing that gateway from the SCP bus to the UBP bus.

 

[ukiltmybrutha]

Long threads, but I skimmed through and took it to read that ForScan cannot read the VSM on an Excursion? without a VCM2 cable...which I thought that I had purchased from the list of supported cables:

https://www.amazon.com/gp/product/B094Z7PBLS/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1

Threads:

2005 Excursion Questions? - FORScan forum

Ford Excursion tire size. - FORScan forum

 

[rjenkinsgb]

I skimmed through and took it to read that ForScan cannot read the VSM on an Excursion? without a VCM2 cable...

Ouch...
That is the interface for the Ford IDS (integrated diagnostics system), that Ford dealers use.
I have one; you probably do not want to buy one.

eg.

Hickleys :: Ford VCM II

Ford VCM II

www.hickleys.com

There are clones for about 1/10th the price, but still not cheap!

 

[ukiltmybrutha]

Ouch...
That is the interface for the Ford IDS (integrated diagnostics system), that Ford dealers use.
I have one; you probably do not want to buy one.

eg.

Hickleys :: Ford VCM II

Ford VCM II

www.hickleys.com

There are clones for about 1/10th the price, but still not cheap!

Do you know of any decent clones at 1/10th the price?

 

[rjenkinsgb]

I'd have a look on the MHH Auto forum, to see if there are any they recommend? That forum is largely devoted to diagnostic gear and software.

I don't have to to look just now, but I can have search tomorrow.

 

[ukiltmybrutha]

I'd have a look on the MHH Auto forum, to see if there are any they recommend? That forum is largely devoted to diagnostic gear and software.

I don't have to to look just now, but I can have search tomorrow.

Appreciate you helping me beating this down. Thanks to everyone here as well.

Was my interpretation correct in that my interpretation of that thread that my current cable will not suffice? Just want to be sure. Good thing is that even with this cable I have learned of all the DTC codes that were sitting around.

 

[rjenkinsgb]

Just had a quick look; apparently the best clones are SP177-C or SP177-C1, they have the same PCB arrangement as the original device - a large main board and a smaller piggyback module.

This listing appears to include the correct thing, but I cannot say for sure.. I can't find any other than on Aliexpress.

https://www.aliexpress.com/item/1005004449133299.html

It's the "Double board A" version that's the recommended one, from what I can figure out?

 

[ukiltmybrutha]

Just had a quick look; apparently the best clones are SP177-C or SP177-C1, they have the same PCB arrangement as the original device - a large main board and a smaller piggyback module.

This listing appears to include the correct thing, but I cannot say for sure.. I can't find any other than on Aliexpress.

https://www.aliexpress.com/item/1005004449133299.html

It's the "Double board A" version that's the recommended one, from what I can figure out?

That's like 1/15th the price given the exchange rate. My wife is from the UK so we are always watching that, lol.

Thanks again, I might try it. Another used VSM is coming this time from an Excursion with that same part number but not a truck. Crossing fingers. Other than that I am thinking ordered 3 pin switches that will run to ground which should also get me above water besides not being able to get the door ajar for those 3 switches.

 

[Kovansky]

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).