Immobilised!

Rocky · Postby **Rocky** » Sun Jul 15, 2007 12:35 pm

Sunday morning, sunny & crisp outside - just right for a morning fang in the 5. Wrong. Hit 'unlock' on the remote - Nothing. Tried my spare remote - again nothing.
So...this woulld have to be the car battery - right??
It has been a bit weak lately & is 6yrs old, and the unusually cold winter here may be enough to kill it.
Is it typical that the immobiliser light on the steering column still flashes but the battery hasn't got enough grunt to operate the unlock mechanism?
Whats the best action - just call the local Dealer, order another Battery & just fit it without worrying about trying to unlock/mobilise it?

manga_blue · Postby **manga_blue** » Sun Jul 15, 2007 1:05 pm

If it was my car then I'd just unlock the door with the key, open the bonnet, switch off the alarm system, get in the car, start it and drive off.

Ben · Postby **Ben** » Sun Jul 15, 2007 2:19 pm

yep sounds like the battery. the last time mine went the same thing happened, the alarm light had enough energy but that was about it

Rocky · Postby **Rocky** » Sun Jul 15, 2007 3:49 pm

Tried it again a couple of hours later & Bingo! disengaged on first try.
I tend to suspect that the state of Battery charge might be implicated.
Still interested in whether anyone else has had similar abberations however - so please let me know if you have.
I am thinking I will just lock it with the key in future as it is rarely parked anywhere that it might be vulnerable.

Andrew · Postby **Andrew** » Sun Jul 15, 2007 7:45 pm

Yes, the top of Mt Dandy kills my car.

Press the remote button from outside the car and nothing happens...... put the remote next to the alarm module and it then triggers the alarm.

Think this is to do with all the radiation from the TV/radio masts located next door to the car park.

Same net result, but different issue i suspect.

Rocky · Postby **Rocky** » Sun Jul 15, 2007 8:06 pm

manga_blue wrote:If it was my car then I'd just unlock the door with the key, open the bonnet, switch off the alarm system, get in the car, start it and drive off.

So...to 'switch off' the alarm system - that would be by removing a fuse from the Fuse Box? Which one?

ducktape69 · Postby **ducktape69** » Sun Jul 15, 2007 9:56 pm

dont think this is possible with the OEM immobiliser, i think he is speaking about an aftermarket alarm...?

manga_blue · Postby **manga_blue** » Mon Jul 16, 2007 3:05 pm

Yep, mine's aftermarket. Switches off with a key on the alarm unit in the engine bay. But even when my car battery so flat it can't turn the motor at all or give the lights more than a yellow glow it still has enough charge to run the immobiliser/alarm system.

Juffa · Postby **Juffa** » Mon Jul 16, 2007 3:22 pm

My aftermarket alarm/immobiliser has its own battery backup. If I disconnect the car battery to do some work on the car I have to remember to disable the alarm siren. The immobiliser function still works. Even days later I can just hear siren quitley screaming away in the background.

I have a hidden bypass switch that allows me to start the car with the key if the remote isn't working for some reason. I think most aftermarket alarms have this feature, not sure about the OEM setups?

J

bruce · Postby **bruce** » Mon Jul 16, 2007 3:32 pm

Yup, cold weather makes the voltage drop. I guess when it warms a little the voltage goes back up a bit. I wonder what the technical term and science is behind this ?

Time for a new battery.

Andrew · Postby **Andrew** » Mon Jul 16, 2007 5:27 pm

bruce wrote:I wonder what the technical term....

Sulfation (for a lead acid battery).

bruce wrote:...and science is behind this ?

link

Alex · Postby **Alex** » Mon Jul 16, 2007 6:18 pm

on the stock NBs there is an alarm box under the bonnet, it's black and cubish with rounded edges, I have seen them sitting behind the airbox or near the manifold
there is a rubber covering over a keyhole, the keyhole is one of those circular ones with 3 positions, off, on, test

Casey · Postby **Casey** » Tue Jul 17, 2007 7:45 am

SM wrote:on the stock NBs there is an alarm box under the bonnet, it's black and cubish with rounded edges, I have seen them sitting behind the airbox or near the manifold
there is a rubber covering over a keyhole, the keyhole is one of those circular ones with 3 positions, off, on, test

Not on standard NB's there's not. Sounds like an aftermarket or dealer fitted unit.

Casey · Postby **Casey** » Tue Jul 17, 2007 7:56 am

Rocky wrote:Tried it again a couple of hours later & Bingo! disengaged on first try.
I tend to suspect that the state of Battery charge might be implicated.
Still interested in whether anyone else has had similar abberations however - so please let me know if you have.
I am thinking I will just lock it with the key in future as it is rarely parked anywhere that it might be vulnerable.

My car did a similar thing a few years ago (at the Boags Brewery of all places). The factory remote stopped unlocking the doors. The spare keys were back at home and a new battery in the remote didn't help. The car still started by unlocking the car with the key and the factory immobiliser chip in the key fob was still working fine and allowing the car to start.

Turns out the remote had a hissy fit and lost its code such that the receiver in the car simply ignored it - the spare still worked fine. Just needed to reprogram it following the service manual proceedure.

Note factory is in bold to identify these items are factory fitted - other sirens, sensors etc are not factory fitted.

You should be fine just locking it with the key - the factory immobiliser and remote unlocking are two seperate systems. The car won't start unless the immobiliser is happy the electronic chip in the key fob has the right code.