SRS Light

I've just fitted a passenger air bag having bought a 2nd hand unit that had been tested (?). I was very careful to disconnect the battery and allow 15 minutes before starting work but having re-fitted every thing I now have a permanent SRS warning light. I tried reversing the 2 connectors to the air bag (they appear to be interchangeable) but it has made no difference. So I suppose the air bag unit may be faulty although it looks fine. I was wondering if there is anything that needs to be reset given that the car has not had a passenger air bag before? I don't have a diagnostic tool (although I can see I may need to get one) so am looking for suggestions. My plan at the moment is to remove the glove box again tomorrow and disconnect the air bag to see if that clears the warning light.

Richard

If I understand you correctly, you have fitted an airbag to the passenger side that you did not have before.
Then I suspect that it needs turning on, so that the ECU can see it.
My Rover 75 can have functions turned on or off using a T4 computer as used by Rover MG equipped garages.
Can't remember if the T4 can be used on the F/TF though.
Some one on here will know, I'm sure.

Suspect that although you have the wiring for a passenger airbag, you don't have the SRS ECU/Control unit for a passenger airbag. Believe that a t4 session is needed to activate it also.

Did the same thing with my Rover 200 years ago and found out the problem. See the link for Rimmers and different ECU's are listed. One for Driver and Pass airbag and another for just a Drivers airbag. Just looked on ebay but can only see the Driver only unit. :nonod:

I think Looney is correct. You need the proper SRS ECU.
I swapped a dual airbag system from one F to a car that had a single bag. I had the same issue with the warning light until I swapped the ECU over as well.

Touchstone, Loony & Rich,

Thanks for the advice guys - I've just disconnected the passenger air bag (giving my back a good workout in the process) and sure enough with the battery reconnected the SRS self checks and the warning light goes out - so at least I haven't broken anything and am no worse off (apart from the cost of the airbag) than before I started.

So it does look like an ECU issue (although the bag could still be faulty) and as Loony says Rimmers list different ECUs for single or double air bags. I do wonder if the ECUs can be re-programed but I will hunt for a replacement ECU at a sensible price. Identifying the correct unit could be a bit of a chaalenge due to MG Rover's process of 'continual improvement'. I've a 2001 1.8i and the unit would appear to have been 'improved' with the launch of the Mk2. I shall try the MGOC technical help to see what they know and report any progress of course.

Richard

Might be worth contacting Russell he has the T4 and may know if all srs ecus can be reprogrammed.:shrug:

David Aiketgate wrote: Might be worth contacting Russell he has the T4 and may know if all srs ecus can be reprogrammed.:shrug:

Thanks David. Provided one of the eBay sellers knows his stuff (??!), YWC 105400 = YWJ 101230 which is the part that Rimmer's list as the '2 bag' ECU for vehicles up to 2005 (it would appear to be backwards compatible). There is a new one on eBay listed for £100 (£160 with Rimmers) but I have found a 2nd hand unit that is around £17 delivered....I'm just checking with the seller to see if he knows what he took it off. You may heve seen I've started a parts number topic to see if anyone knows how to crack the code between what's printed on the unil and what is listed in the parts catalogue.

Richard

Hi Richard,

Cant get onto to Rimmers at moment to check (as i'm at work :coat: ). But have a look at this link for ebay who claims to offer a twin SRS ecu for a reasonable price

MGF MGTF AIR BAG ECU MODULE ACTUATOR AIRBAG PART NO. YWC 103380 TWIN AIRBAG Completed

OK - I've ordered a used SRS ECU off eBay for £17 delivered so not a total disaster if it doesn't solve my problem (I can always relist it). From some extensive research I've found that:

1 - the part number for a single airbag ECU is YWJ101220
2 - the part number for a double airbag ECU is YWJ101230
3 - the YWJ numbers have no obvious correlation to the YWC number actually printed on the units (a totally crazy 'system')
4 - it would appear that YWJ101220 = YWC105230 (single bag ECU and YWC 105230 is what is currently fitted to my car)
5 - it also appears that YWJ101230 = YWC105400 and that is the part on the way to me
6 - expert opinion (well .org) suggested a T4 reprograming is also required but anecdotal evidence (Rich for example - I know who I believe)suggests that if you have the right unit it should be OK when connected.
7 - Rimmers want around £160 for a new unit. An eBay seller has new units for £99. I used Breakerlink to get 3 quotes ranging from £40 to £50 delivered for a used unit or £66 for a new unit delivered. They are listed at £13 on eBay

Assuming the SRS ECU does the job, the total cost of fitting the airbag including delivery of 2 items will be £57....has I ordered the ECU with the bag from the same seller it would have been £53.

I'll let you know what happens after I change over the ECU (and take the glovebox out again to reconnect the passenger airbag). Meantime if anyone wants a clean ash grey blanking unit together with the foam backing, just let me know.

Richard

When i take a passenger airbag out the car example mark 1 mgf ywc 103380 mark 2 ywc 105230 early tf,whether it as a passenger airbag or not the part number remains the same,i suspect You are locking the ecu up,by adding the passenger airbag as it is not switched on to recieve the passenger.

The mg rover mgf airbags in my expeirence seem to rarely activate in a accident. Most cars have sensors on the chassis rail a lightest of nudge can send them off.Also a key switch to simply turn off the passenger if a child seat is common practice,why this wasnt incoporated and a passenger airbag fitted as standard in especially late mark 2 and mgtf i never understood.

I dont fit airbags to our customers cars i refer them to MG MAIN DEALERS summit garage.Probably worth ringing mike there they quite helpful.

I've just collected this from the PO:

I plan to fit it tomorrow (when it is forecast to be dry) and that should reveal the 'truth' about part numbers and whether a T4 programming is also necessary to make the passenger air bag live. I'll report back of course and if the SRS system shows-up as passing the self test with the passenger air bag connected, I'll do a 'how to fit a passenger air bag' topic.

Richard

Fingers crossed. :yesnod: