You have answered this yourself.

 

Well it was my idea, just wanted to pick other peoples knowledge before diving in

 

The lower B pillar cover is all you need to remove to gain access, but disconnect the battery for 15 minutes before you play with yellow wires.

 

I have a pretensioner fault too. I was wondering what could I check before I can say that the pretensioner is faulty. I have read that it is rarely the pretensioner, the fault is mostly due to the wiring. Tell me what to check, Where to measure resistance and what value should I expect. Regards

 

on my spider, after alfadiag telling me about an airbag pretensioner problem on the passenger seat, and cleaning the connector under the seat numerous times, i discovered that alfadiag (or the fault codes) doesn't know that it was a right hand drive car and so the passenger seat was actually the driver seat, i don't know if it's the same for the 156

 

My car is a Left hand drive. I ´ll Try and see if I can clear the fault with fiatecuscan or unidiag. Well if you know anything else I can do on my 156 please tell me.

 

Can somebody please tell me where to check for the pretensioner fault, I get a open circuit or short circuit in the drivers pretensioner. I have read to check the wiring under the seat, however I thought that wiring went to the side airbag. Correct me if I am wrong. Do I need to check the wiring under the seat?

 

Hi I checked the B pillar on my 156. Could only disconnect kind of cleaned contacts and reconnected them. However the fault is still present when I connect the examiner. Can someone tell me what the correct resistance on a pretensioner should be? wanted to know if the pretensioner is faulty or only the wiring. Can someone guide me please. Have faults on both pretensioners, it started only with the driver´s side then it turned to both. HELP

 

Hi Saade, I`m the same boat with the drivers pretensioner fault, Did like you to no avail. Can anyone out there advise the next move before I go and get a new / second hand pretensioner to trouble shoot. Can I swap sides to see does the snag move ? ................tks in advance.........Dannyboy.

 

check the connection at the B pillar, also check the connections at the centre tunnel just before the ECU's connector.

 

Thanks Lacken 156, I`ve checked the "B" pillar connections.........will now check the ones at the ECU.
Rgds...........dannyboy.

 

Hey dannyboy I checked the connections in the B pillar however no difference. I have not checked connections in the ECU. However it might be a problem with the ECU itself, I guess. I hope it is not. I had given up on this fault, however I will keep an eye on your progress, may be you can be my guide in clearing this fault.

 

> near < the ECU not > in < the ECU

might also be worth while removing the connector the the ecu, giving it a clean up & fitting it back in again.

 

I know not in the ECU, But the Connector attached to the airbag ECU. Once I get a chance I´ll try and do it. Please keep me informed if someone has managed to clear this error. I heard somewhere that the ECU might get damaged by jumpstarting the engine. I´ve done it several times, hope this is not my case.

 

Hi Gent`s, at the first available opportunity, I will check the ECU connections, give them a spray of switch cleaner, check will the fault clear and get back to you. It would be a help to see what is the resistance at the good ( passenger side ) pretensioner connection is compared to the bad drivers side. I presume I have no chance of blowing anything if i`m only checking the resistance ?
Rgds...............Dannyboy.

 

Hey dannyboy if you have resistance date please share it with all of us. I have both pretensioners faulty, so I cannot asume any values I get are coherent. Please let us know how you get on with your problem

 

Hi Saade, will do..........just can`t get the time to get to it at present , but it has to be done. NCT
( Irish MOT ) is due in Jan . I`ll toying with the idea of checking the resistance on the good l/h passenger pre tensioner and comparing it to the faulting , drivers side , one. I`ll have a word with one of my electronic engineering type buddies first , don`t want to blow the pretensioner. If one was that way inclined , perhaps a way around it to pass NCT while waiting for a proper fix would be to hang in a correct value resistor...... but I wouldn`t be that way inclined..............will keep you posted..........Dannyboy.

 

Hi gent`s , got a little time during the xmas holiday. Asked some of my electronics friends. They have experience with troubleshooting aircraft fire bottle squibs....ie......just like the air bag.....they get a signal and blow the explosive charge which in this case, empties the fire bottle into the engine or freight hold in the event of a fire. They advised to use a recommended moving coil type meter but should be o.k. , but not recommended , ( at your own risk ) with a digital multimeter. Borrowed a meter and went about it .
Took the precautions, Battery disconnected for 30 min at least, Initially got confused by the side airbag sensor which is mounted on the "b" post beside the pretensioner and has the same yellow connector blocks. The wiring diagram in e-learn is good on this ...the lead in is ....airbag- description, Airbag- wiring diagram, Airbag-location of components, airbag-functional description .

The moving coil meter packed up.....giving unreliable readings so I took a chance using my digital multimeter. Disconnected the connectors to the pretensioner and measured the resistance. With the ohmmeter set to 200 on the scale the readings were 00.7 on each pretensioner ( the good and the bad ) moving further up the scale really only gave me zeros. ......which now leads me to believe the problem lies with the airbag ECU or its connections. The drivers pretensioner showing the fault would not reset (as before ) using Fiatecuscan, after remaking all these connections at the pretensioners...........next step ECU .................rgds...........Dannyboy.

 

Definitively the ACU, make sure you get the same type same number ! from a breaker
around 50 quid, a new one 180 !!!

 

Hi Rarebare, is it hard to get access to the airbag ECU and it`s connections ?.........is it located forward of the gearlever ?..............tks in advance ..........dannyboy

 

Hi Rarebear, i`ve just copped the ACU ( crash sensor ) is different to the ECU ( Control unit ) . Do you think I should chase the ACU or the ECU for this pretensioner problem ? Where is the ACU located ?
rgds...............Dannyboy

 

forget the term ACU, its an ECU for airbags.

your problem could be a bent or corroded pin.

 

Hi Lacken 156, I`ve been studying e-learn wiring diagrams and component locations since and it looks like the only other items that could give me this problem are the other connections from the pre tensioner wiring to the ECU which seem to be near the ECU ( loc on the transmission tunnel fwd of the gear lever ) , the connections to the ECU itself and then the ECU . If the connections all look good and the fault won`t clear after clean up with switch cleaner and reconnection , I`m going to chase a secondhand replacement ECU.........that`s the plan.......if I don`t win after that the only other thing I could think of is to fit a known good ECU and see what happens. Getting one of those could be difficult.
Rgds...............Dannyboy

 

what p/n is the ECU?

Also check INSIDE the yellow or orange connector, there could be broken wires/pins

 

Good news !, airbag light went out and is staying out approx 6 starts since I disconnected/ reconnected both pre-tensioners despite the fault not clearing with fiatecuscan software after everything was reconnected. I`m presuming it reset itself when it saw the fault had gone.....the timing does equate to approx 6 starts. Here`s hoping the problem is sorted. I`ll get the NCT ( Irish MOT ) done quickly while it`s still out ....fingers crossed...........tks for the help gents........Dannyboy.