Immobiliser?

[Flatplane8]

Evening all.

I've just put a new battery in my car ('97 4.2) and held down the fob key whilst re-connecting the positive lead. Lights flash and the alarm works fine. However the MiL light doesn't come on nor can I hear the fuel pump going.

The little slot for the USB-like key also has no light on it. I've been through the sync process several times with the same result.

With the old battery, all was normal except it didn't have enough power to start the car.

Any ideas or wisdom?

If the immobiliser has failed or has stopped talking to the alarm, is there a way to bypass it? Appreciate this isn't public info.

We're about to start on a body off project, but I haven't heard it run for 18 months and would love to know that the engine at least starts before I take the car to bits.

Thanks,

Simon

[ukkid35]

Flatplane8 said:

I've just put a new battery in my car ('97 4.2) and held down the fob key whilst re-connecting the positive lead.

Sorry I can't help, but I'm wondering whether you have any documentation

I've never done anything special when reconnecting the battery, just need to disarm with a single press after connecting

Although there's a page in the drivers manual, it mentions 3 flashes when locking, whereas mine flashes 5 times

Is this telling me something or is the manual wrong?

[LLantrisant]

i had a similar issue after i had a totally flat battery for several times:

first time i re-charged the battery and all was fine
2nd time i re-charged the battery and it still was fine
3d time i re-charged the battery and things were not fine anymore:

central locking was playing mad, door-opening was playing mad:
finally i bypassed the immo, sent the alarm system to a specialist to check it. (and it was fine)
after that i was follwing the procedere with the fob for the central locking /alarm and it was ok again.

[Flatplane8]

Thanks guys. I'm leaving it over the weekend and will try again next week. normally the re-sync procedure works well, but only the alarm is responding this time.

[Robscim]

ukkid35 said:

Sorry I can't help, but I'm wondering whether you have any documentation

I've never done anything special when reconnecting the battery, just need to disarm with a single press after connecting

Although there's a page in the drivers manual, it mentions 3 flashes when locking, whereas mine flashes 5 times

Is this telling me something or is the manual wrong?

Hi Paul,

My experience is that you do have to hold the button down when you re-connect (it didn't work when I didn't!!) but remember this will shut and lock the windows so make sure the boot is open when you do it in case it doesn't work!

I get 3 flashes if that helps and did when Carl replaced the alarm unit.

Cheers

Rob

[Juddder]

ukkid35 said:

I've never done anything special when reconnecting the battery, just need to disarm with a single press after connecting

Yes, no need to hold any fob button while reconnecting the battery

I've removed my battery a lot - especially with all the electrical gremlins I have had - and the process I use is:

- Disarm the alarm with the fob
- Disconnect the negative lead first

Do all the other things you want to do such as charge battery, replace it etc.

- Reconnect the negative lead last
- The car will beep and auto-lock itself

Press the fob as you fancy to disarm the car and enable the door button mechanisms

Works without failure everytime - just in case it helps at all

[Juddder]

Flatplane8 said:

Lights flash and the alarm works fine. However the MiL light doesn't come on nor can I hear the fuel pump going.

The little slot for the USB-like key also has no light on it. I've been through the sync process several times with the same result.

Just remembered I had something similar when one side of the silver switch had corroded and come off of the key switch

This stops the fuel pump priming and the red dash board light coming on

I just replaced it with a push switch

So I'd suggest the easiest way it to remove the car stereo or ash tray, get your hand on the back of the key switch and twist the securing nut off of the back and then you can pull out the switch to check

If you just connect the two wires to each other you can rule out or not this as being the problem

HTH!

[Flatplane8]

Thanks all for your advice, I've managed to bypass the immobiliser and it fired right up. Nice to hear it again after 18 months.

[ukkid35]

Flatplane8 said:

Thanks all for your advice, I've managed to bypass the immobiliser and it fired right up. Nice to hear it again after 18 months.

Awesome well done

[Juddder]

ukkid35 said:

Flatplane8 said:

Thanks all for your advice, I've managed to bypass the immobiliser and it fired right up. Nice to hear it again after 18 months.

Awesome well done

Had my running yesterday too - does make you happy