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MG MGF Technical - False alarming

Hi,

We have a 2001 MGF. Don't know if anyone has had problems with the alarm sporadically going off. I can't lock ours now because the alarm more often than not sounds (cheering up the neighbours). I took off the volumetric sensor in case that was causing it, but still the same. BTW, it has had a major clout on the drivers door and we've had it back from the bodyshop about 2 weeks, but the problem has only appeared in the last 2/3 days. Any ideas?

Thanks in anticipation.
PT Greenwood

The damage repair might be a coincidence, because Fs are prone to interference from all sorts of radiation if you get a bad one - microwave ovens, police radios, mobile phones, both receivers and transmitters. Could any of these be the cause?

Chris
Chris

There were some reports of this a while back if you check out the archives. If the alarm components themselves have not been damaged/faulty.It maybe down to some kind of localised electro-magnetic influence. Have you recently changed your mobile phone for example, as there were instances like mobile phones / transmitter masts etc close by triggering alarms.

Keep us posted :)
Steve P

Beat me to it Chris :)
Steve P

Hmm.. I'm a bit new to this BBS. Just did a long reply and lost it somewhere so excuse me if I duplicate.
The missus took it to work and had the prob yesterday. I wondered about interference so asked her to park it in a different part of the car park - same. Neighbours told me it was going off last night here (at home) too last night (and tonight). No mobile phone inside. Currently trawling the archives but it looks like the wiring in the boot and the drivers door lock are the most likely suspects at the moment. I found a good tip about fooling it into thinking that the boot is open by shoting the feed and taking out the bulb so the alarm won't set. Good for the time being whilst I search for the cause.
Thanks for the replies and welcome any other ideas.
Phil
PT Greenwood

The driver's door lock isn't above suspicion, but the only straightforward way to check is to have the alarm ECU interrogated by TestBook. Was the repair done by a dealership bodyshop? If so, you might be able to persuade them to run a diagnostic free of charge. Having said that, I had a similar problem which TestBook kept identifying as a fault in the driver's door lock, but after replacing the lock twice to no avail they tried a new alarm ECU and that cured it. Technology, eh?

If you're worried about security you can disconnect the horns, at least that way the car can be locked without cheering up your neighbours ;o)
Mike Hankin

Hi Mike,

Thanks for that.

I live in Trowbridge but the car goes to work in Bristol. Where would you say the best place to take it to to get it interrogated and how much do you think it might cost? Sounds like an idea to do that first (besides, it raining)

Thanks

Phil
PT Greenwood

Having gone all DIY in recent years I've no personal experience of the local workshops, but the SWMGF crowd is gathering for lunch today so I'll ask around.
Mike Hankin

My alarm would sound about 12 seconds after setting it.My then local Dealership spent two days working with MGR who changed everything but still got a volumetric alarm message on TestBook.
They concluded that I must have a Secondary Aftermarket System fitted. Yes, it has a Tracker fitted which I had told them about and was written on the Worksheet.
Off to the Tracker Shop. They disconnected the battery, removed the Tracker, reconnected the battery and all was OK. Advice from Tracker Engineering was that this was impossible so put it back. It has not sounded since (except checking on the Annual Service).
The Dealer then told me that at no stage had they disconnected the battery.
It was concluded that ReBooting the system had corrected a computer error. (Sorry IT Experts ).
This is always worth a try.
An Annual function check is always a good idea. At the same time, check that the Door Key Code is working.
Geoff F.
G. Farthing

Hi all, latest in this saga. Thought I had is sussed - found the drivers door switch lock asseembly (replaced for new item by bodyshop after accident) was sopping wet after the rain, dried it out and covered it in gaffer tape to keep it dry.

Tested it - still the same. Disconnected the battery and reconnected after 5 mins and alarm behaved perfectly with no false alarms.......until the wife took it to work today and it started off again when she parked up. @@**!!!++@@! Anyway, booked into SMG Bristol who appear to know what they're talking about (I am ex-motor trade myself so I have low expectations of garages I'm ashamed to say)

I'll let you all know what happens. Thanks for the help so far.

Phil.
PT Greenwood

I've had this in the past, it was the door latch mechanism. Sounds quite feasible as you say your door had been damaged?
Paul Lathwell

Ah ha! Here's a clue (if you know how to interpret it) When the alarm is faulty (which is all of the time now) moving the sill buttons up or down on either drivers or passenger's side does not make the motors work - they are dead even when the door is unlocked with the key, however they motor up and down with the keyfob. Thsimeans I cannot do the fault diagnosis procedure now. Also when the fault ocurrs (see above) the remote range is reduced to about 1/2.

Seems to me that the mechanics are working OK but the ECU is not giving out the LOCK/UNLOCK command with the key or the manual pulling/pushing of the sill button.

BTW the boot wiring was OK and although one wire had cracked insulation there was no shorting.

I'm starting to think that the wiring around the radio area is suspect or the ECU. I'm guessing it's mounted under the radio? Anyone know how to remove the MG radio cassette and fascia so I can gain access to the wiring?

I got a quote from SMG in Bristol for testbook investegation and they said said they need it at least an hour and it will cost £75+vat. Called Chippenham motors and they said 20 mins and £35+vat. No contest you'd think, but the guy in Bristol seemed to really know what he was talking about and the guy in Chippenham didn't! DOH!

Any help gratefully received.
PT Greenwood

Hi PT,

Pull out the centre vent. It needs a good tug.

You will then have access to the wiring loom at the back of the radio.

If you then need to remove the radio head unit (assuming it's the original one), loosen the 4 allen screws which are accessed via small holes on the radio facia and pull it out.

Good luck!

Sam
Sam Murray

This thread was discussed between 28/12/2006 and 03/01/2007

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