Airbag light on / seatbelt pretensioners

Sausage · 2022-04-04 22:19:05

Hi. I have a 2005 Expert which has the airbag light on. It has the seatbelt pretensioners on the belt itself in the B pillar and drivers airbag only.

I have been struggling to find information due to the sheer amount of different vehicles and all the results I can find are either for newer models or for pretensioners on the receiver stalk rather than on the belt.

I have plugged it into pp2000 and get:

Air bag ECU
Permanent fault. Seatbelt trigger (left and right). Open circuit.

The previous owner told me the airbag light came on after a minor parking nudge. The airbag hasn’t deployed but I do not know how you tell if the pretensioners have fired or not. The seat belt runs and locks smoothly as you would expect it to, the wiring is intact and undamaged and the airbag ecu unit under the floor is dry and spotlessly clean.

I have read about resetting the airbag ecu, replacing it, replacing just the pretensioners, replacing it all. I don’t want to just throw money at it until it’s solved as the parts are expensive and also could do with resolving the problem swiftly, so am hoping someone can point me in the right direction to finding what the fault is and getting it working properly.

It desperately needs to go for an MOT soon as it has expired and is parked on the road. I do not know anyone who would turn a blind eye to the airbag light being on.

Thanks.

tee_cee · 2022-04-05 10:39:07

Sausage wrote:

Hi. I have a 2005 Expert which has the airbag light on. It has the seatbelt pretensioners on the belt itself in the B pillar and drivers airbag only.
I have been struggling to find information due to the sheer amount of different vehicles and all the results I can find are either for newer models or for pretensioners on the receiver stalk rather than on the belt.
I have plugged it into pp2000 and get:
Air bag ECU
Permanent fault. Seatbelt trigger (left and right). Open circuit.
The previous owner told me the airbag light came on after a minor parking nudge. The airbag hasn’t deployed but I do not know how you tell if the pretensioners have fired or not. The seat belt runs and locks smoothly as you would expect it to, the wiring is intact and undamaged and the airbag ecu unit under the floor is dry and spotlessly clean.
I have read about resetting the airbag ecu, replacing it, replacing just the pretensioners, replacing it all. I don’t want to just throw money at it until it’s solved as the parts are expensive and also could do with resolving the problem swiftly, so am hoping someone can point me in the right direction to finding what the fault is and getting it working properly.
It desperately needs to go for an MOT soon as it has expired and is parked on the road. I do not know anyone who would turn a blind eye to the airbag light being on.
Thanks.

Well you have done everything right so far.
Someone may correct me, but I think this light is used for low brake fluid also. May be worth a look.

kenbw2 · 2022-04-05 13:30:35

Mine was much older - 1999 model - but when my brake fluid was low I got the low brake fluid light. Red one with the brake drums that looks like ( ! )

Last edited by kenbw2 (2022-04-05 13:30:56)

vaz2121 · 2022-04-05 13:57:51

The information you have makes it difficult to decide where the issue is ............
It maybe possible that although any wiring for this system looks ok it might be defective ..................
Something in my memory says air bag module is in a recess on floor under the middle passenger seat and is prone to damp or filling with water [I have a 2005 dispatch van and on checking ... Mine suffered wetness in recess].......................
Check everything wiring wise ... cruddy connections ,broken wires etc ...................
Also there was some similar talk a while back about a resistor to resolve a similar issue on mk 1 and facelift vans or it was possibly berlingos and resistors ...................
Sorry ... Not very helpful but something to think about ..........................

Sausage · 2022-04-05 16:33:21

Cheers for replies. I reckon it’s got crash data stored in the airbag ecu and from other peoples experience with different PSA vehicles of this vintage, needs either replacing or sending off the have the data reset (can’t be done from PP2000).

The pretensioners definitely aren’t open circuit and the cables and connectors are ok. The airbag ecu module under the floor is dry and appears undamaged.

I am going to try to find a replacement 2nd hand unit first I think. There is nothing that matches the same part number available currently but apparently the part numbers don’t need to match and I just need to find a module with the same spec? Not sure how you go about figuring that out!

Pathfinder100 · 2022-04-15 12:10:55

I had a similar problem. I used a hack that JohnDragonMan used on his Iveco to get it through MOT.

Mine is something to do with the wiring under the drivers seat. if you change the seat height and tilt angle it will go off, but it's no good for me doing that since i'm 6' 3. I've tried contact cleaner with no joy. Will probably strip it out this summer and failing everything else use a dummy plug on the cable to bypass whatever sensor is in the seat.

kenbw2 · 2022-04-15 21:41:26

Pathfinder100 wrote:

I had a similar problem. I used a hack that JohnDragonMan used on his Iveco to get it through MOT.

Was this something about a relay and a timer wink

Actually I don't think you need that anymore. I remember looking into it and the light doesn't need to illuminate on the first turn of the key

JohnDragonMan · 2022-04-17 00:58:27

kenbw2 wrote:

Pathfinder100 wrote:
I had a similar problem. I used a hack that JohnDragonMan used on his Iveco to get it through MOT.
Was this something about a relay and a timer
Actually I don't think you need that anymore. I remember looking into it and the light doesn't need to illuminate on the first turn of the key

more like just wiring the bulb into another that turns off after a while like the EML. our iveco has a faulty anti shudder valve which works perfectly but the ECU cant read its position (open or closed) so the EML stayed on. so i wired it into the oil pressure light

thing is with our vans, the air bag system is really simple. just the air bag and 2x seat belt pretensioners. given the wiring is fine usually its just the airbag module under the floor acting up. cut the carpet back and just replace it and all will be well. it will have gotten damp and corroded the PCB or connector.

Last edited by JohnDragonMan (2022-04-17 00:59:23)

Pathfinder100 · 2022-04-17 17:30:27

It's on the list of maintenance jobs for this summer.

Sausage · 2022-04-20 12:51:41

I sent the airbag module off to be reset and fitted and the light is still on. It has cleared the right (drivers) seatbelt trigger fault but the left remains. So I decided to dig a little deeper and continuity test the pretensioners. The driver side gives a constant 2.6ohms but the passenger side starts with 0 then rises to and settles on 11.5ohms so presumably the pretensioner is faulty. Will try unplug it and stick a resistor in the plug to see if that solves it and then replace if so. Probably be next week before I can get a resistor and try it. Luckily my dear old mum has agreed to host the van on her drive until I’ve got it sorted so time is less of an issue, beyond me wanting/needing to use it.

Sausage · 2022-04-26 19:32:25

Fault was with passenger seatbelt pretensioner. Plugged a 2.5ohm resistor into the plug and voila the light is no more.

Time to replace with new.

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#1 2022-04-04 22:19:05

Airbag light on / seatbelt pretensioners

#2 2022-04-05 10:39:07

Re: Airbag light on / seatbelt pretensioners

#3 2022-04-05 13:30:35

Re: Airbag light on / seatbelt pretensioners

#4 2022-04-05 13:57:51

Re: Airbag light on / seatbelt pretensioners

#5 2022-04-05 16:33:21

Re: Airbag light on / seatbelt pretensioners

#6 2022-04-15 12:10:55

Re: Airbag light on / seatbelt pretensioners

#7 2022-04-15 21:41:26

Re: Airbag light on / seatbelt pretensioners

#8 2022-04-17 00:58:27

Re: Airbag light on / seatbelt pretensioners

#9 2022-04-17 17:30:27

Re: Airbag light on / seatbelt pretensioners

#10 2022-04-20 12:51:41

Re: Airbag light on / seatbelt pretensioners

#11 2022-04-26 19:32:25

Re: Airbag light on / seatbelt pretensioners

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