What's this? Airbag blues.

[TomsFocus]

I'm now off for the night so won't be able to reply again until tomorrow.

The loom probably is the same on all Galaxy's but they're not really my area, I'm more Fiesta/Focus/Mondeo. 

@unofix might have correct wiring diagrams?

Might be worth opening up the box on the driver's side to see how that's wired to compare them.

10 minutes should be enough for the capacitors to discharge but you can leave it longer for your own peace of mind if you like.

 

 

[johnjohn10]

If the white wires are part RCM Dtc and also part of the seatbelt Pretensioner isnt there a specific spot they go to? 

[johnjohn10]

1 minute ago, TomsFocus said:

I'm now off for the night so won't be able to reply again until tomorrow.

The loom probably is the same on all Galaxy's but they're not really my area, I'm more Fiesta/Focus/Mondeo. 

@unofix might have correct wiring diagrams?

Might be worth opening up the box on the driver's side to see how that's wired to compare them.

10 minutes should be enough for the capacitors to discharge but you can leave it longer for your own peace of mind if you like.

 

 

Then take the box apart leave it apart and reconnect the battery and that's OK? 

[johnjohn10]

I'll have to leave it for the night too, the car is at my mother's house and I need to Go home. I'll be back tomorrow afternoon.

Thanks for your help. 

[TomsFocus]

3 minutes ago, johnjohn10 said:

Then take the box apart leave it apart and reconnect the battery and that's OK? 

Yeah that's fine.  Just don't plug it back it in while the battery is connected as that can cause a power surge which could theoretically set off the airbag.  (Though I've never heard of it actually happening).

Sorry though, I've just realised what you mean.  The white wire plugs have been totally bypassed and soldered together, right?  

So in that case, I'd say it's probably better to check the driver's side, and unplug the white wires on that, which should hopefully throw an open circuit code for the driver's seat.  (Don't worry, it'll clear when plugged back in)

Once we've confirmed those soldered wires are definitely for the belt pretensioner and causing the original fault code, we then need to find the break in the wiring. 

It's possible the pretensioner itself is faulty, but will be a pain to test now that the plugs have been removed and soldered.  If it's not the pretensioner, then you'll have to look for another break, somewhere under the carpet between the soldered part and the airbag ECU.  ECU is probably under the centre console, but again, I'm not 100% sure on the Galaxy.

[johnjohn10]

1 hour ago, TomsFocus said:

Yeah that's fine.  Just don't plug it back it in while the battery is connected as that can cause a power surge which could theoretically set off the airbag.  (Though I've never heard of it actually happening).

Sorry though, I've just realised what you mean.  The white wire plugs have been totally bypassed and soldered together, right?  

So in that case, I'd say it's probably better to check the driver's side, and unplug the white wires on that, which should hopefully throw an open circuit code for the driver's seat.  (Don't worry, it'll clear when plugged back in)

Once we've confirmed those soldered wires are definitely for the belt pretensioner and causing the original fault code, we then need to find the break in the wiring. 

It's possible the pretensioner itself is faulty, but will be a pain to test now that the plugs have been removed and soldered.  If it's not the pretensioner, then you'll have to look for another break, somewhere under the carpet between the soldered part and the airbag ECU.  ECU is probably under the centre console, but again, I'm not 100% sure on the Galaxy.

How would I run forscan on the separated box to see what faults come up with the battery disconnected? Isn't that what you suggested? "Can you unplug the other plugs on the seat, switch the ignition on and run Forscan to see which fault codes that creates?" 

The white wires lead nowhere from out the back of the box at the top left corner, they are fed from front top left corner by the wires I circled in red in the picture, that come up out of the floor loom. 

The seat belt wires are soldered to wires that come up from the floor loom, that I can now see used to feed the two cut wires at the front of the box that I have circled in green in the photo. So the seat belt used to plug into the back of that and someone has taken it out and cut the front feed and soldered them together, circled in blue. It's the same connection, original I'm guessing, just bypassing the box connection. 

[johnjohn10]

So inside the box the only wires that are actually connected to anything wired coming out the back of the box and leading somewhere is the airbag, circled in green. The wires at the bottom have no receptors inside the box. I'll take a picture of inside tomorrow. 

[TomsFocus]

11 hours ago, johnjohn10 said:

How would I run forscan on the separated box to see what faults come up with the battery disconnected? Isn't that what you suggested? "Can you unplug the other plugs on the seat, switch the ignition on and run Forscan to see which fault codes that creates?" 

The white wires lead nowhere from out the back of the box at the top left corner, they are fed from front top left corner by the wires I circled in red in the picture, that come up out of the floor loom. 

The seat belt wires are soldered to wires that come up from the floor loom, that I can now see used to feed the two cut wires at the front of the box that I have circled in green in the photo. So the seat belt used to plug into the back of that and someone has taken it out and cut the front feed and soldered them together, circled in blue. It's the same connection, original I'm guessing, just bypassing the box connection. 

Separate the plugs with the battery disconnected.  Then leave them unplugged and reconnect the battery.  Then run Forscan to see which fault codes come up.  (Then disconnect the battery again before plugging anything back in.)

The point of this is to work out which plugs are for the seat pre-tensioner.  But if you're sure the soldered wires are for the belt pretensioner then we can skip that step altogether.

I think what has happened is someone has cut the seatbelt wires too short when bypassing the plug block and soldering them.  That means that it worked fine to start with, but when the seat was next rolled right back for a taller occupant, the wires have snapped somewhere under the carpet or been pulled out of the plug at the airbag ECU.

[johnjohn10]

4 hours ago, TomsFocus said:

Separate the plugs with the battery disconnected.  Then leave them unplugged and reconnect the battery.  Then run Forscan to see which fault codes come up.  (Then disconnect the battery again before plugging anything back in.)

The point of this is to work out which plugs are for the seat pre-tensioner.  But if you're sure the soldered wires are for the belt pretensioner then we can skip that step altogether.

I think what has happened is someone has cut the seatbelt wires too short when bypassing the plug block and soldering them.  That means that it worked fine to start with, but when the seat was next rolled right back for a taller occupant, the wires have snapped somewhere under the carpet or been pulled out of the plug at the airbag ECU.

Ah that's an idea. Have you any experience with tracing wires back to airbag ecu? Sounds like a bit of a job, do I have pull up the carpet and take off of peices off the car interior to get the the ecu? I bet I do hey. It's in the center console I read, in front of the gear shifter. If I got a resistor I could test the theory hey, cut the wires and put the ones from under the carpet onto the resistor right? If the fault stays then there is some broken connection under there, if the fault goes then its from the seat belt pretensioner /buckle right? Is a 2.5 ohms resistor good for this system? 

What about the disconnected white wires that are getting fed from the loom? Does every wire into the black box have something to do with the srs? I'll keep looking for an electrical schematic. 

Thanks for your help! 

[TomsFocus]

7 minutes ago, johnjohn10 said:

Ah that's an idea. Have you any experience with tracing wires back to airbag ecu? Sounds like a bit of a job, do I have pull up the carpet and take off of peices off the car interior to get the the ecu? I bet I do hey. It's in the center console I read, in front of the gear shifter. If I got a resistor I could test the theory hey, cut the wires and put the ones from under the carpet onto the resistor right? If the fault stays then there is some broken connection under there, if the fault goes then its from the seat belt pretensioner /buckle right? Is a 2.5 ohms resistor good for this system? 

What about the disconnected white wires that are getting fed from the loom? Does every wire into the black box have something to do with the srs? I'll keep looking for an electrical schematic. 

Thanks for your help! 

I have traced wires back to the airbag ECU but not in a Galaxy.  In the 2008 Fiesta and Focus it is in front of the gear shifter, just needs a few pieces of trim removing but nothing major.  I would hope it'll be in a similar place on the Galaxy.

Yes, if you cut the wires and fit a resistor to the ones coming from the airbag ECU that should prove the fault.  I don't know the Ohm specs needed unfortunately.  If you're buying a proper airbag bypass resistor online, the seller might be able to confirm which is best for these.

Not all the wires in the block are for SRS.  Seat heating also goes through there.  Did we confirm yours doesn't have heated seats?

[johnjohn10]

7 hours ago, TomsFocus said:

I have traced wires back to the airbag ECU but not in a Galaxy.  In the 2008 Fiesta and Focus it is in front of the gear shifter, just needs a few pieces of trim removing but nothing major.  I would hope it'll be in a similar place on the Galaxy.

Yes, if you cut the wires and fit a resistor to the ones coming from the airbag ECU that should prove the fault.  I don't know the Ohm specs needed unfortunately.  If you're buying a proper airbag bypass resistor online, the seller might be able to confirm which is best for these.

Not all the wires in the block are for SRS.  Seat heating also goes through there.  Did we confirm yours doesn't have heated seats?

Hi no there is no heated seats. 

So I've spent 4 hours today trying various combinations of things, I was able to get some 2.2 ohms 1/2 watt resistors today and cut the line from the seat belt that was soldered and wired in the resistor, ran forscan again same fault. So then to test the resistors I took the black box apart and connected the resistors to the airbag clips and ran forscan again, as that wa not giving any faults, that came back with an airbag fault this time, so either I didn't wire them in well enough or the resistors aren't working. I didn't strip the airbag wires and it was a tricky go to get them in so not being connected well enough is a possibility. But then! When I put everything back together the way they were and cleared all modules in forscan and ran the scan again the airbag fault has remained 😞

There's 2 extra codes I think now, I attached a photo, ones a BCMii relating to the airbag if can remember, and the other is a 2nd RCM code now. 

[johnjohn10]

Just to be sure I'm Doing it properly when i discharge the capacitors I'm disconnecting both positive and negative then taking the positive and connecting that to ground on the car with a jumper cable and leaving that for about 5 minutes. 

[johnjohn10]

Wired in 2.2 ohms 1/2 watt resistor. 

I also made a 2 pronged tester with 1.5 mm solid copper wire about 1.5 inches long on each side of the capacitor I taped to the wires. I tried that after trying to just put the capacitor wires into the airbag connector that then came back as a fault but the pronged tester I made also came back as a fault but I know for sure they were touching the connectors and that airbag circuit had no faults when it was connected. Would the 1.5 inches on either side of the capacitor of 1mm solid copper wire increase the resistance thereby giving a fault reading? And why would the fault code stay there when I put everything back the way it was and cleared the module and tests again? 

Other picture is inside the black box. Only the yellow airbag connector has a anything connected out the back. 

[unofix]

Without seeing the actual vehicle and without a full set of Ford wiring schematics I'm not hopeful of being able to diagnose this. This is not a fault in the normal sense, it is the result of someone butchering the cars electrical system and we have no way of knowing whats been done.

Do both the passenger and driver seats have side airbags ?

I suspect that the vehicle does not have its original front seats and this is the reason for the attempt to bypass the SRS.

https://7zap.com/en/catalog/cars/Ford/S-MAX%2FGalaxy/S-MAX%2FGalaxy 2006- (CA1)/bGxpcXFiQnhPTjlwTzNSYTU2TDBiUT09--/10110->13166/36014|---Wiring+-+Seats/

[johnjohn10]

23 hours ago, unofix said:

Without seeing the actual vehicle and without a full set of Ford wiring schematics I'm not hopeful of being able to diagnose this. This is not a fault in the normal sense, it is the result of someone butchering the cars electrical system and we have no way of knowing whats been done.

Do both the passenger and driver seats have side airbags ?

I suspect that the vehicle does not have its original front seats and this is the reason for the attempt to bypass the SRS.

https://7zap.com/en/catalog/cars/Ford/S-MAX%2FGalaxy/S-MAX%2FGalaxy 2006- (CA1)/bGxpcXFiQnhPTjlwTzNSYTU2TDBiUT09--/10110->13166/36014|---Wiring+-+Seats/

Hi just seeing this message, somewhat new to this site and it's a bit tricky to for me navigate messages sometimes. 

Someone has definitely been at the wiring feeding into the ecu in the central console, I pulled the carpet up a bit and there's electrical tape wrapping up the bundle of wires and there were two other wires soldered together but the solder had broken, I connected then rescanned made no difference. I also tried a 3.3 resistor on the seat belt feed wire, made no difference still an rcm fault. 

I couldn't follow that link you sent me so I did my best to navigate to the files in my own, not sure I got the right spot, attached a screenshot. So that little box with the wires in the schematic is what I'm talking about yes, is there somewhere to get the wiring diagram. For where the wires go from that little box user the seat? Yes there's side airbags on the seats. my seats are manual seats, the driver has one electric adjustment button but the rest of the adjustments are manual. The seats are fabric base model seats I'm guessing but they all match throughout the car. Not heated seats. Why do you suspect someone changed the seats?

Thanks for your help. 

[johnjohn10]

On 3/28/2023 at 2:37 PM, TomsFocus said:

I have traced wires back to the airbag ECU but not in a Galaxy.  In the 2008 Fiesta and Focus it is in front of the gear shifter, just needs a few pieces of trim removing but nothing major.  I would hope it'll be in a similar place on the Galaxy.

Yes, if you cut the wires and fit a resistor to the ones coming from the airbag ECU that should prove the fault.  I don't know the Ohm specs needed unfortunately.  If you're buying a proper airbag bypass resistor online, the seller might be able to confirm which is best for these.

Not all the wires in the block are for SRS.  Seat heating also goes through there.  Did we confirm yours doesn't have heated seats?

I've tried a 2.2ohms resistor and a 3.3ohms, the fault stayed. But someone else told me that the elm327config I had would not be helpful in my car with FORScan and would make things worse giving false readings. It's this one. https://www.amazon.co.uk/gp/aw/d/B07MQ8GHG3?psc=1&ref=ppx_pop_mob_b_asin_title

I now have more faults than I started with for no real reason that I can see, if something I tried didn't work I put it back the way I found it. 

I read in one of your other posts that you'd never seen a seat belt pretensioner give up a fault code without deploying? So do you think my situation is not the seatbelt Pretensioner? God my brain is starting to melt. What about if I got my ecu srs cloned with a new clean program would that take care of the fault codes or would it still set it off? Just replace the entire srs program. 

[johnjohn10]

On 3/29/2023 at 9:11 PM, unofix said:

Without seeing the actual vehicle and without a full set of Ford wiring schematics I'm not hopeful of being able to diagnose this. This is not a fault in the normal sense, it is the result of someone butchering the cars electrical system and we have no way of knowing whats been done.

Do both the passenger and driver seats have side airbags ?

I suspect that the vehicle does not have its original front seats and this is the reason for the attempt to bypass the SRS.

https://7zap.com/en/catalog/cars/Ford/S-MAX%2FGalaxy/S-MAX%2FGalaxy 2006- (CA1)/bGxpcXFiQnhPTjlwTzNSYTU2TDBiUT09--/10110->13166/36014|---Wiring+-+Seats/

So in the schematic from ford that box does only have 3 connections, just like mine, so of the 3 wires in the little box under the seat, in my car one of those wires is the airbag colour so I guess that's the airbag, the other was the pretensioner, that connection is also accounted for, been cut at that plug and soldered with the seat belt wire bypassing the box connection, so there is only one wire remaining and that is the grey colour top left plug that the cut white wire is coming out the back, the seat isn't heated or any electric motors, so could that be a 2nd wire for the air bag system? Could it be a weight sensor? if so would that create an open circuit in the seat belt pretensioner circuit or somehow give a fault like that? What does Ford say that is? There are only 3 in the schematic and 2 are accounted for. Is there a part number in my seats I could look at if that would help? 

[unofix]

I have not been able to find any wiring information for your model. Which makes it very hard to guess what it has now and what it should have. This is a list of things that could have been connected to the seat, but each model does things a little different.

1. One pair of wires to the seat belt pre-tensioner - command (to fire the explosive charge)
2. One pair of wires to the seat belt buckle - sensor (to detect when fastened)
3. One pair of wires to the seat pressure pad - sensor (to detect when someone is sitting)
4. One pair of wires to the seat side airbag -command (to detonate the airbag)

 

[Tizer]

6 minutes ago, johnjohn10 said:

so could that be a 2nd wire for the air bag system? Could it be a weight sensor?

This is a general comment but probably applies to your car as well.

Normally a cars front passenger seat has an Occupant Load Sensor. If there is a frontal impact and the Sensor is showing that there is no one in the seat then the Front Passenger Airbag will not deploy. Obviously the Drivers seat does not need one.

The Side Airbags would normally only deploy if there is a Side Impact.

Have you has a look at the PID's in the RCM to see if they throw any light on things.

[johnjohn10]

10 minutes ago, unofix said:

I have not been able to find any wiring information for your model. Which makes it very hard to guess what it has now and what it should have. This is a list of things that could have been connected to the seat, but each model does things a little different.

1. One pair of wires to the seat belt pre-tensioner - command (to fire the explosive charge)
2. One pair of wires to the seat belt buckle - sensor (to detect when fastened)
3. One pair of wires to the seat pressure pad - sensor (to detect when someone is sitting)
4. One pair of wires to the seat side airbag -command (to detonate the airbag)

 

🤔 The pair that go to the seat belt that have been soldered are in the buckle itself, I pried it open to see, they both right there together. Then theres the air bag they accounted for, so does that leave most likely wires to the explosive charge in the pretensioner? That would be more likely than a pressure pad wouldn't it? And if that was disconnected it would give up then open circuit fault too wouldn't it? 

[unofix]

2 minutes ago, Tizer said:

Obviously the Drivers seat does not need one.

Why ?  🤣

only kidding. That actually used to be a very common problem with LHD Mustangs which were converted to RHD. It was easy to not connect the seat load sensor on what had become the drivers seat but very difficult to fit a load sensor on what was now the passenger seat. Many conversions just had the system wired as if there was always a passenger even when there was not.

[johnjohn10]

But the pictures I've seen. Of the seat belt pretensioner for this car only has the one set of wires. 

[unofix]

Whats the pre-tensioner and the buckle like on the drivers side ? How many wires are there ?

Does the vehicle detect when the passenger and/or drivers seat belt(s) are fastened ?

[johnjohn10]

11 minutes ago, unofix said:

Whats the pre-tensioner and the buckle like on the drivers side ? How many wires are there ?

Does the vehicle detect when the passenger and/or drivers seat belt(s) are fastened ?

Driver side detected yes don't know about passenger, that's a good idea.

I haven't compared the two I will do that.  Thank you for the ideas. 

You know what else I haven't done is put a resistor in the 2 cut disconnected white wires! 🤦‍♂️Omg not saying it would definitely be a fix but like that's pretty dumb of me not to try. I'm claiming noob status on that one. 

[johnjohn10]

1 hour ago, johnjohn10 said:

But the pictures I've seen. Of the seat belt pretensioner for this car only has the one set of wires. 

Oh I guess that could be pretensioner with no unfastened alarm on it sure.