308 SW hdi Random seat belt warning alarm activation

[ajr_2010]

Hi All,
I am having a problem with random seat belt alarm activation in the rear seats of the car. The seat belt alarm will be activated with no one sitting in the seat and no heavy objects on the seat . Some times the alarm will be triggered even if the seat is occupied and the seat belt is in use. I have seen suggestions that it could be triggered by damp in the sensor or connection this could be the cause because we had a long dry period and it was fine . Also suggestions that this could be fixed either by removing the sensor or using water dispersal spray like WD40 on the connection or the sensor. Has anyone had this problem and what solution did they use ?
My ideal solution would be to use the water dispersal spray where to spray on the connector is clear but where to spray on the sensor ?
Also should this fail would unplugging the sensor ( i don't think removing it is necessary) affect any other safety equipment like airbag operation ?
Kind regards
Alasdair

 

[En Cavale]

Hi, I am also interested a solution to this issue. The rear seat belt alarm in my 2011 308 SW activates randomly and intermittently when the seats are unoccupied. It is driving me insane. Sometimes it's the middle seat, sometimes the left, sometimes the right, sometimes a combination. I have tried fastening the seat belts, unfastening the seat belts, seats up, seats down. No difference. The Peugeot mechanic was not able to find a solution either. If there are any helpful suggestions please fire away.

 

[dimistyle]

Of the 2x 308 SW we have with rear passengers on any given day they both have had this problem and have not cured it but disconnected the under seat sensor.

Seems to be a common fault on the wagon overseas as well and any temporary fix comes back again.

Lift rear left seat and remove, take plastic inner door surround off, just unclips.
Lift carpet can't remember if the plastic seat locators need to be removed

Lift carpet and by the polystyrene protector there is a connector. You can try contact cleaner or just leave it disconnected.

The red overhead lights turn off after a while and no more warning sounds

 

[En Cavale]

Thanks v.m. I have discovered a connector plug underneath the left rear seat carpet, but it has multiple wires going in to it. I haven't disconnected it yet as I don't know what they all do. I am looking for a wiring diagram in the owner's manual.

 

[seasink]

Beware of airbags. I have a Cit C4 diagram, which is the 308's nearest relative - here:

 

[Dijon16]

That is spooky because my C5 X7 has started doing the same thing. Sometimes it is all the unoccupied seats, mostly it is the right rear. Nothing has changed, except it had a service recently, and it only started after that, but I do not see how that could be the cause.

Usually I just leave the belt clipped in as it is only rarely occupied.

 

[dimistyle]

Another good option Dijon16, leave the belts plugged in, this also fails after a while as you will notice some belts are not identified as being plugged in. From memory RH and middle are somehow linked together and LHS is separate. On both vehicles I tried both belt positions just in case they had a preference, I even pulled apart one of the seats to see what the sensor type is as it works by weight on seat i.e school bags, but gave up and disconnected the damn thing as mentioned above.

Interesting diagram above, not sure which is the back row or 3rd row of seats? Im guess the dotted line must be the rear but only shows 2 belts with sensors?

 

[En Cavale]

Thanks for the wiring diagram seasink, it looks pretty close to my 308. I'm still not 100% certain which is which, so I am unplugging the wires one-by-one, hurt locker style. Keep expecting one of them to activate the air bag and blow me out of the car.

 

[driven]

That is spooky because my C5 X7 has started doing the same thing. Sometimes it is all the unoccupied seats, mostly it is the right rear. Nothing has changed, except it had a service recently, and it only started after that, but I do not see how that could be the cause.

Usually I just leave the belt clipped in as it is only rarely occupied.

You are correct. Ghosts exist in cars

Check out the Renault 4 first up in Cape Town

 

[Dijon16]

, I even pulled apart one of the seats to see what the sensor type is as it works by weight on seat i.e school bags, but gave up and disconnected the damn thing as mentioned above.

That may be the case in other cars, but the rear seat cushions in the C5 X7 are located by springy metal stays and can be removed in seconds flat.

I think that someone said that there is a foot pad. In this case it sounds more logical because there are no visible wires to the seats, and it has only happened since the rain, so maybe the footwell is a bit damp, i will check it out.

 

[dimistyle]

I would say on the 308 SW at least the sensor bar under the middle row seats is made up of several coverd over a row of flexible ribbon cable moisture has some affect on this sensor bar. In the UK forums they have been replaced only to fail again and obviously they have more damp conditions.
I might strip this one apart to see how these are connected to the 4 pin connect

 

[dimistyle]

I couldn't stop myself so there are 3 circuit boards with induction coils and well coated with an epoxy layer over the electronics.

No signs of water damage or corrosion so my be a coil has failed?

 

[Kenny432]

99.9% of customers quoted for repair say no so we just configure it out in BSI.

This just stops all the bells and whistles