AIRBAG FAULT DF072 & DF071

[Blackcube]

Hello all.

Renault Megane 1.5 DCi, 5 Door, 2005

I am new to the megane family and am well aware that this is common problem my service light is on along with the icon of airbag. I have read up alot and done alot of research. Below is the exact listing of what i have done, and have also scanned the system and exact coding below.

SCAN:

Circuit 1 and Circuit 2

DF071 - PR110 Line 6 Impedance 99.9 ohm
DF072 - PR109 Line 5 Impedance 99.9 ohm

Driver Side Front AIRBAG.

REPLACEMENTS:

So taking this all into consideration, I have replaced the rotary switch unit, driver steering wheel airbag, cleaned the plugs a little, cleaned the connector under the seat of driver and passenger side (just in-case) and light is still on and the icon.

I was wondering if the circuit is open, but thoroughly inspected the cable and could not see anything, i know people say looking is no good, but i just wanted to try, im not very experienced in cars.

If any help could be given or assisted it would be great!

P.S. I have the idea of cutting the connector under drivers side and just re-soldering all the wires to their match, and see if it works without the plug. however, in doing this, if this doesn't fix it, then i have just reined a connector for nothing.

Many thanks

[Blackcube]

.. BUMP. Please help if anyone can. Thank You

[Blackcube]

UPDATE:

OK, so i have decided to take off the rotary switch and check all connection ports. all connections seem to be active. i tested with a multi meter and power is drawn from all cables on the rotary switch. so it is not that.

I have a doner car and i am intending to take the doner car driver seat and test it in my car, the doner car seat i do not want as teared to peices and broken pannels, however the doner car had no airbag issue. so i will test with the doner car seat

If this fixes the issue then i know that is is one of the connections to the pre-tentioners and/or a broken cable along the lines.

If this does not fix the issue, then i am assuming the only other issue it could be, is what people say all along, that the driver harness connector has open circuit, in which case, i will cut off the connectors of the doner car, and re-solder them to my car, giving fully working connectors + plug, hoping that this will fix the issue as i can not think of anything else that it could be.

I Will not cut the cable and re-solder the connectors and plug if it isnt that as that would be a waste of time and effort.

I will update this post on my progress to help other people with the same problem.

If anyone has any extra idea's to help, it would be greatly appreciated.

Many thanks

[freelanderuk]

I can not help but thanks for the update

[Gumby6371]

Can add much except airbag faults are usually a bad connection somewhere in the system, electrical contact cleaner and a needle file on all connections is my usual plan of attack.
One thing I will say tho is be VERY CAREFUL with multi meters on air bag circuits, they have been known to set the airbags off!

[Nathan1577]

hi does the fault point to which airbag it actually is. there are 4 possabilities for the drivers front wether it be a 3 door or 5

theres the obvious drivers steering airbag, drivers seat air bag, drivers nearside pre-tensioner and then if its a 5 door you will have an offside pre-tensioner and if its a 3 door you will have an under seat airbag instead which is designed to raise your knees out of the crumple zone.

also test the resistance ocer each airbag either at the bag or the conector. you should be looking for 2-3 ohms for a healthy bag

regards
nathan

[Blackcube]

Hello Nathan thanks for your reply.

I belive it said something about pre tentioners, however is both value of 99.9 then there is open circuit so I am unsure on how to approach this. I do not want to get a whole complete new wiring loom as I would have to litterly take apart the whole seat.

Problem still persists and can not put in for an mot. Would like some advise even if it temp get rid of the lights to pass mot

Thanks

[Nathan1577]

hi i would take the connector off where it connects under the seat, if i remember rightly there should be 6 wires going to it. there are 2 rows of pins but all 6 wires are on the same row and in pairs next to each other. for example if the wires went to pins 1,2,3,4,5,6 1 and 2 would be the pretensioner, 3 and 4 would be the airbag and 5 and 6 would be the other pretensioner or base airbag. test them in pairs and check for that resistance. if all appears fine then you have a break in the wire before the connector and then you just need to check the 6 lengths of wire as far back as you can go for continuity until you find the problem. if you dont get the resistance reading, unplug the 3 plugs which conect to the 3 airbags/ pretensioners if you cant get the correct resistance with one of them then it is that airbag/pretensioner that is at fault. if not check the continuity of the 6 wires between the plug under the seat and there respective plug at the airbag, no continuity obviously indicates a broken wire and your best bet is to just run a new wire.

[wilko447]

I had same problem airbag warning light always on...I checked wiring block under seats cleaned connectors with a small brush then sprayed the whole plug with electrical spray....reconnected it and the light was gone been fine ever since...in my case it was obviously just a dirty or bad connection in the block.....