Air Bag Light

[Jeffers]

Hi I am new to Citroen Owners. My wife and I have just got a 2004 Pluriel, which we love, but the airbag light is on all the time. It has been on for over a year apparently it has been in to Bellamys of Croydon, who say  it has a DTC of "R/H Airbag Igniter open circuit". They have checked the loom under the seat etc. Does anyone have any other info or possibly a wiring diagram which I can use to check the system out. I am a trained mechanic but just need a little info if possible. :rolleyes:

[paul.h]

Welcome to the forum.

I am surprised it got through an MOT if the light has been on over a year and that your Citroen dealer could not fix it. If the air bag light is on, it also means the air bag system is disabled so may not work in an accident - it could affect your insurance. Also, there is a court case today where somebody crashed their car with the passenger air bag disabled and has been done for murdering the passenger.

 

There is a wiring diagram in the Haynes C3 manual but I do not know if it is the same as the Pluriel. You also need to be careful with the wiring colours and identification nos. since Citroen often change these. If you want one specific for your car, these are included on the Citroen dvd manuals you can get from such as ebay for about £10.

 

It may be worth undoing and redoing the connectors under the seats a few times in case these are giving a poor contact - but if doing any work on the air bag system, always disconnect the battery first and then wait about 15 mins for the air bag system to power down. I have not worked on an air bag system but suggest the following (others may provide better info): It is also probably not wise to use an electrical ohm meter to check for continuous circuits in case the current it puts down the wires sets off an air bag. Also, keep the driver's window open whilst the battery is disconnected so the ignition key can be used from outside the car in case an air bag goes off when powering up again.

 

The following procedure for disconnecting the battery I have found does not give problems on our C3:

 

- remove the ignition key from the car

- open the bonnet

- wait a few minutes for the BSI to shut down

- disconnect the battery negative terminal

 

When reconnecting

- ignition key out of the car

- reconnect the battery

- wait a few minutes

- insert the key in the ignition and wait a minute

- turn the key to the first position and wait a minute

- turn the key so the dash lights come on and wait a minute

- start the engine

- take the windows down and up to reset the anti pinch

- reset the clock (and radio on the C3).

 

 

 

 

I did a google search and this came up on a Pug 206, being the best post that may help.

 

Quote: The airbag system does NOT have sensors which check the system constantly.
The only sensors are the impact sensors which consist of a ball bearing in a tube of high viscosity jelly, under an impact of >80 g the ball is forced through the jelly to complete the circuit and set off the airbags.
The system is controlled by an ecu, and if the system detects any open or short circuits in the wiring it will memorise a fault and illuminate the light to let you know you need to take it to a dealer.

The most likely causes are the connections under the 2 front seats for the seatbelt pretensioner and for the side airbags if they are fitted, simply a case of cutting the connector out and joining the wires with a heatshrink solder type sleeve.

The other possibilites are a faulty comm 2000 unit, this would cause a 'drivers level 1 igniter open circuit or short circuit to earth' fault, though it is less common but not unheard of for these units to develop airbag problems.
The actual airbags never usually cause faults.

There could also be a faulty ecu, or a power supply problem to the ecu.
If your battery has recently been flat then it can cause 'temporary supply voltage' and 'passengers airbag deactivation not defined' faults too.