RCM Module Fault, advice from the knowing please...

[Maninavanwivadog]

Hi All
I was hoping for a steer or some advice on the above? I bought 3 months a go a 2017 Transit Custom 2.0, which i am converting into a camper after the death of my old Mk7. I have been using it as a daily driver for that time until i got a flat battery. Easily jump started, charged overnight and all is well. However, unfortunately after the jump start my airbag light came on!
I got out the Autel code reader and also Forscan and both showed an RCM fault code relating to passenger side seat belt pretensioners. I could not clear the codes permanently on either system, as both showed the problem as not fixed.
I traced the wiring from the drivers side seat to connector and RCM under the seat, but on the passenger side absolutely nothing? No wiring, no cable no pretensioer circuit at all. is this normal for 17 plate?
I am most perplexed by the fact that the dash warning light is only just showing, as clearly its been ok the last 12 weeks., but the circuit hardware is absent.
At the risk of answering my own question, i am a bit lost if anyone could chime in with some help. Mot due in 3 weeks, hence the ask!
Cheers

[Frag]

The seatbelt pretensioner is part of the belt reel itself,not the buckle.
Any wiring to buckles is purely for warning light / chime.

It will definitely have a pretensioner on drivers seatbelt reel as it will have drivers airbag.

Generally,if you don’t have a passenger side airbag,there won’t be a passenger pretensioner.
(You’d have to check the reel to confirm,as I can’t remember off top of my head.)

Also be aware,the connector into reel pre-tensioner (so usually yellow wiring) has an orange locking clip to lock it in place.
The resistance through circuit changes if this is released or pushed home,so if you have the reel plugged in and connected,but the orange locking clip isn’t pushed in, it will cause a fault …..

[Maninavanwivadog]

Hi Frag
Many thanks for the reply, which all makes perfect sense. Youre right, no passenger airbag (pov spec) so hence the absence of wiring in the passenger seat.
I'll see if i can inspect the drivers side tommorow and update. thanks again for the advice.
all the best mark

[Maninavanwivadog]

I've also found the fault code that the reader says which is B007f:11-8B Passenger seat belt pretensioner deployment control CMDTC's and ODDTC. Does this help as now out of my depth a bit

[Frag]

That would suggest that even though It has no passenger airbag,it does have a passenger seatbelt pretensioner.
So I’d be removing the B pillar trim and check the wiring / connector into the seatbelt reel itself.
(There is no pretensioner on the centre seatbelt reel,on a twin passenger seat)

Have you drilled any holes in the floor around / under where the passenger seat is ?
Do you still have a twin passenger seat fitted in its factory position ?

[Maninavanwivadog]

Hi Frag
'Every day is a school day', even at 60! I did as you advised pulled out the B pillar trim and could see the pretensioner connections as you described. It all looked fine with no wire damage or corrosion. I was able to do a continuity test as best i could back to RCM, and the machine which goes 'beep', beeped. I was happy no breaks in the wire despite having dismantled half the interior.
To answer your question, the seat looks original and judging by the muck under the lift up seat bases was either original or not been moved in a very long time. No holes drilled in the floor or anything out of place.
Ran the code reader again and nothing changed so gave all the connections a desperate wiggle and sprayed with contact cleaner. To my surprise and happiness code was able to be deleted and stayed off. If only it was always that simple!
I had put a 12v light switch on the B pillar, so on entry i could put on the additional 12v lights in the van. Maybe i caught something in doing that but it was a task from 8 weeks ago.
Without your help i wouldnt even have known where to look.
Am extremely grateful for you taking the time to help and advise.
Much respect.
All the best Mark

[Frag]

Good result,
It could very well have just been a bad connection at the reel itself.

I asked about the seat with you saying it’s a camper conversion,as I’m sure there is wiring running across the floor/rubber mat under seat to b pillar,and have seen people / converters mount items under the passenger seat and drill down through that harness.
I’m fairly sure the wiring from the airbag module to pretensioners on B pillars is in that loom too.
(Best path from where RCM is,and to try and minimize number of connectors inline,less chance of these kinds of problem)

With fords diagnostic tool you can datalog the RCM and see the actual resistance through that circuit on live data which helps with diagnosis,we also have ‘dummy’ simulators,basically a resistor to plug in and mimic a seatbelt assy at correct resistance…

As long as you’ve sorted it,it’s all good.