1998 940 2.3 LPT Automatic Immobiliser Problem

[Volvanman]

Hello there,

I have a 940 with the same problem and am stranded 90 miles from home!

I purchased a new remote fob from eBay about 6 months ago, and it paired fine. It was working perfectly until a few weeks ago where it seemed a bit sluggish, and sometimes needed several presses before it operated. Other times it would work first time. I was sure it couldn't be the batteries, but am not so sure now.

What has happened is that having locked it as usual with the remote, trying to unlock it later had not worked. I have been able to gain access to the car by unlocking manually, but this has caused the immobiliser to operate. There is no alarm, but all indicators & interior lights flash together. I read that there is a five second starting window when this process stops, but that has not worked. Once the flashing stops, operating any door/the ignition or anything else simply restarts the flashing.

I am at a loss. I really need to get the car operational in order to get home. I have just paid a large amount for MOT remedials, a winter service, cambelt & power steering pump, and so really don't want to lose this car. I use it as a van - I am an electrician, and will be very lost without it!

If anyone can help I would be very grateful!

Kind regards -

Jerry Walker

[Steve940estate]

What age is your car and type of keyfob ?
Depending on what age you car is I might be able to help but because you are a new member of the forum there is always the worry I could be helping someone steal a car !

[Volvanman]

Hello Steve940estate,

Thank you for your reply - & I fully understand your reservations!

My vehicle is a 1997 940. The fob has 2 buttons. One large one with LOCK UNLOCK printed on it in the same typeface as the dashboard numerals if that makes any sense? The other button is smaller and has no wording on it, and if pressed (before the car disgraced itself today!) it seemed to operate the immobiliser, in that it caused all of the indicators to flash - my car seems to have no audible alarm. Between the two buttons the word VOLVO is in raised letters - part of the moulding of the body of the fob.

I could kick myself really, because as described, the fob had been playing up a bit lately & I was convinced that the batteries were in good order & that therefore there must be some sort of fault with the receiver or beyond...

Please ask any other questions to relieve suspicions that I may be a dubious character - I'm really not!

I had to let my 1988 vintage 740 go due to electrical issues, and really love this car. As I mentioned, I use it as a van, and with the towing springs fitted it is a superb workhorse. I'm working in the Huntingdon area & need to be able to travel home to Lincolnshire on Wednesday evening, so am really desperate - please help!!!!!

Kind regards,

Jerry

[Steve940estate]

It's a shame it's the later alarm by the sound of things. The early ones can be got round quite easily which is probably why Volvo made the later ones more complicated.

The later ones are a problem as from what I have read they are linked to the engine ECU. I'm not sure if the immobiliser works from the alarm or from a chip in the key. There are a few threads about alarms some like this one suggest removing a fuse is enough but that seems a bit too easy. some people say it is nessasary to swap the engine ECU (behind the panel by your right foot) and swap it for one from an earlier car without the immobiliser. I don't know if any re-wiring is needed then to connect things back up.

Keep looking on here as someone might be able to offer some more help either by doing a search of previous threads or another reply.

A new set of batteries in the fob might help even disconnecting the main car battery for a while might re-set it but I'm really not sure.

The type of alarm you have is a Volvoguard 2 or II it might help is you are searching on here.

[Volvanman]

Thanks for the reply Steve,

Annoyingly, back home (90 miles away), I have a non running identical model bought off eBay for spares. It has been a big saving as I have pillaged it for many parts. If I swap the ECU on the non runner for the one from the spare (assuming the non runner's ECU is working), will that sort my problem?

Awkward, as I now have difficulty getting home, but would that be a potential solution?

Thanks again -

Jerry

[Steve940estate]

Unless it's an earlier car, pre 96 I think it's probably got the same ECU you already have.
Late ECU's need a signal to allow the car to run, early ECU's don't. Some but not all later cars also have a chipped key.
As I said before I don't know if the signal to the ECU comes from the alarm or the chipped key reciever. If it does come from the alarm fitting an early ECU should work.

I hope that sort of makes sense, I am guessing really. Hopefully someone with a later car can offer some more advice.


The last time someone was having problems with the later alarm I thought it might be useful to find out how they worked but having an early car I can only study the wiring diagrams.

[scarlett2904]

hi all

i am new to the forum and i need help.

i have a 1997 volvo 940 celebration which i have had since new, done 140.000 miles with no problems to speak of.

came out this morning pressed the fob to unlock the car and nothing, checked the batteries in the for all ok tried the spare fob and still nothing.
in desperation i unlocked the car just on the key which started the flashers going, tried to stop them on the fob, nothing! put key in ignition all lights up but wont start. I have ckecked all connections fuses etc all appear to be fine, the flasher came on every time i opened the door after manually locking it or put the key in the ignition and tried to start it set them off but no start.

My question is does anyone know the problem, i dont need to have an immobiliser and could do away with it if thats the problem, can it be bypassed. the sticker on the windows says volvoguard.

any help would be usefull as i cannot use the car at the moment.

thank you

[gpl1968]

Yes, the immobiliser can be disabled by removing the alarm module and bridging two terminals with a jumper wire.
If you remove the glovebox the alarm module will be fisible on the left hand side.
See the applicable attached pdf for the correct bridging connections.
The central locking and ignition will still work with this modification.

[scarlett2904]

Originally Posted by gpl1968

The attached pdf may help.
It describes how to bypass the alarm. It is for the 960 but the alarm is the same so the bypass should work.
You will need to remove the glovebox to gain access to the alarm module.

Hi I cannot get the attatchment to diarm the immobiliser.

Scarlett2904

[Laney760]

I've got no working fob at the moment, I assume it's my battery but I havent had time to buy one but I am still able to use the car without a problem but when I've had your problem before there is reset procedure, I can't remember it now? I'll take a look using the search procedure in a minute

I can see the attachments,when I click on them they are downloaded to the lower left of my screen as pdf files and I simply click on them there to open them