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MG MGF Technical - Immobiliser, alarm & carpet problem

Hi All,

I want to re-new the carpets, all advice is to disconnect the battery (seat belts etc) however the guy who tried (and failed) to repair my alarm/immobiliser, when I was last in UK, advised against this as it may well cause another immobilser problem - which has never been fully operational or reliable. The "passive" immobilisation as described in the handbook has never operated (luckily)and I do not have the EKA code. Questions:

1.Can I risk leaving the battery connected and take out the seats? What effect may this have?

2. How do I get an EKA code? Car is a 1996 F export model.

As ever many thanks

Elona

E J Davies

Hi Elona,

On point 1. I didn't know you had to disconnect the battery to take seats out. So I merrily went ahead and unplugged the under seat connection and took out my seats.

I did this twice, then came across this board where it says you must not remove seats, or more specifically the under seat connector, without disconecting the battery.

It never caused any issues, but yes, i now do disconnect the battery.

Don't know if this helps

Brian
B Buick

Elona,

The seat belt tensioners have an explosive charge in them. It is possible that connecting them while the battery is hooked up will set them off.

You're probably going to have to disconnect the battery at some time in the future, so why not do it now, if you want to fit a new carpet set.

I replaced my black carpets with a beige set some time ago. It is a fairly easy job. You will need a "torx" head to remove the bolts securing the seats.

You can get the EKA code from here....

http://www.mgrovercodes.com/
Sam Murray

Sam,

Thank you. As ever I have follow on questions. If I disconnect the battery, what effect will this have on the immobiliser? If it creates a fault will I be able to correct it via the EKA code?

Many thanks

Elona
E J Davies

It shouldn't create a problem - merely requiring the fob to be resynchronised by half a dozen successive button presses once the car battery has been reconnected.
However I don't know what your previous immobiliser problem was, nor whether you have the radio code.
All manuals say don't do it without disconnecting the battery first, but as Brian suggests, the system can been disconnected without necessarily going off.
If you do leave the battery connected, it is probably worth waiting 15 minutes from when the ignition was last switched on. This would allow any reservoir charge to dissipate (under normal operation all SRS systems have to be able to work on stored charge without the battery voltage being present).
Charless

I would get the immobiliser problem fixed as a high priority job, the carpets can wait. If your battery were to fail without warning, as mine once did miles from anywhere. Great looking carpet won't get you home. A new battery will as long as the immobiliser problem is already fixed. Being in fear of disconnecting the battery because it will not run, is really not a good idea.
Playing with the wiring of the SRS with the battery connected is not the best of ideas, if it were to trigger the explosive charge with your hands not far away, it would be a risk not worth taking, other people might have got away with it, you may not be so lucky.
Why do all the service date books tell you to disconnect the battery, because there is a risk to your safety. Get the immobiliser problem out of the way, then carry out the carpet change in safety.
Gary Luxon

All,

Thank you for all of the advice so far. I ahve been in touch with http://www.mgrovercodes.com/, however they cannot find the code for my car. Does anyone know where I can get the EKA code for an export model?

Regards

Elona
E J Davies

Hi Elona,
Even if the EMA code was on record, there is no guarantee that it is still your current set code. You need a testbook analysis to find that out - and I doubt there are many(any) reasonably priced ones over there!
The consequences of locked out/no radio issues in your location with the lack of backup assistance, I would risk the 'live' disconnection of the pretensioner connections. Just be certain that the ignition has not been switched on in the immediately preceeding 20 minutes.
We are all forced to wear seat belts all the time, but they have only ever been of any use to anybody in (at best) less than 0.00000000000000000000001% of the time we are driving. And as Brian suggests above, the pyrotechnics take a very specific trigger to operate - but all manufacturers walk in terror of lawyers.....hence the doom laden warnings.
Charless

The disconnect is not the problem Charles, it is the reconnect that has the greatest risk. The pyrotechnics are old and could become unstable, some Manufacturers recommend the units are replaced after a set period due to stability issues. Lets not forget they are chemical charges that are set of by a very low trigger voltage less than the full battery voltage, so in the event of an accident and the battery was lost the remaining milliseconds of power will set off the charge maximising protection. I would not risk it without knowing the stability of the chemistry.
Gary Luxon

Gary, I don't wish to be rude but the 'reconnect' happens every time every single "old" car (of any make) in the world fitted with airbags switches on the ignition circuit in the normal way - ie many, many millions of times every day. The evidence would suggest fairly universal chemical stability.
I believe you don't need to worry about this everyday event quite so much. Be interested, but don't be terrified; and airbags are universally triggered by current, not voltage.
Charless

I am aware of the firing system being current, I simplified it to make it easy for non technical readers.
There is good reason why the makers place such warnings. Having spent all my working life in technical fields, I can see the dangers of a false trigger, caused by a static discharge or intermittent momentary connection. when the ignition is switched on there is no current flow to the air bag only the pcb. however the onboard electronic can detect an impedance change when the airbag circuit is reconnected, this does have the potential to cause the electronics to give a false trigger on earlier systems.




Gary Luxon

Elona,
whilst this bbs is very good, if you join
www.mg-rover.org and contact one of the modds username: technozen , he may be able to better advise about the immobiliser. He has capability of fob coding etc and the wiring of teh car. If he doesnt know how to fix it, then I suspect there isnt a fix.

sorry for advertising another forum, but due to technozens expert knowledge on this subject I thought it would be OK.
David Mills

This thread was discussed between 20/05/2013 and 17/06/2013

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