Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Big_Al on 02 January 2013, 17:45:39

Title: Imobiliser key "chip" question.
Post by: Big_Al on 02 January 2013, 17:45:39
hi guys ,
             have been trying to find out that if the "chip" in the key becomes loose , & the car was already running & driving ,

if the chip moved for example , taking a sharp turn & the bunch of keys rattle into the main key , could that cause the engine to cut out .

What I am trying to say is:  Is the engine running dependant on the imobiliser sensor in the ignition barrel , being in constant

contact with the key chip?

And if the chip moved ( by vibration or being knocked ) could it cause an instant cut out of the engine?

Or does the imobiliser sensor just need an initial chip confirmation to instruct the ECU that it is the correct key  as the key is inserted & turned .

Hope this question makes sense

TIA   Al  :-\ :-\

Title: Re: Imobiliser key "chip" question.
Post by: dbug on 02 January 2013, 17:50:40
Believe immobiliser chip only used in starting up - no effect whilst driving.
Title: Re: Imobiliser key "chip" question.
Post by: Entwood on 02 January 2013, 17:53:26
Interesting question ...when mine was causing problems due to a loose chip it only ever affected starting ... once running it never "cut out" at all ...

so on that basis I'll agree with dbug

:)
Title: Re: Imobiliser key "chip" question.
Post by: Broomies Mate on 02 January 2013, 20:01:42
I agree with the above.

The ECU only requires the signal from the chip on initial start-up.  It doesn't 'cycle' needing a constant signal.

There is potential here for the Ignition Barrel to be faulty, losing contact with movement allowing the car to cut-out.  I've never experienced it on an Omega, but the likes of the MkIII Cavalier, it was a reasonably common problem which starts off very intermittent and becomes worse quite quickly.
Title: Re: Imobiliser key "chip" question.
Post by: TheBoy on 02 January 2013, 20:08:23
I concur, the immobiliser is only used at startup.
Title: Re: Imobiliser key "chip" question.
Post by: Big_Al on 02 January 2013, 21:10:16
I agree with the above.

The ECU only requires the signal from the chip on initial start-up.  It doesn't 'cycle' needing a constant signal.

There is potential here for the Ignition Barrel to be faulty, losing contact with movement allowing the car to cut-out.  I've never experienced it on an Omega, but the likes of the MkIII Cavalier, it was a reasonably common problem which starts off very intermittent and becomes worse quite quickly.

Could it be a possible loose wiring connection on the barrel  ? I think this was suggested earlier .

Could anyone point me to a picture of the said barrel  . . so I can see what I am looking for  wiring wise  :-\ :-\

Can only wait now to see if there is a further breakdown  . . but all ok now for 3 days  ;) ;)
Title: Re: Imobiliser key "chip" question.
Post by: Broomies Mate on 02 January 2013, 21:16:27


Could it be a possible loose wiring connection on the barrel  ? I think this was suggested earlier .

Could anyone point me to a picture of the said barrel  . . so I can see what I am looking for  wiring wise  :-\ :-\

Can only wait now to see if there is a further breakdown  . . but all ok now for 3 days  ;) ;)

Turning the key moves contacts within the ignition assembly to excite the ignition circuit, then move a further position to power the Starter Solenoid.  This is sprung loaded to turn itself back to the ignition position.

The problems I have experienced in the past (again, not with Omega's) is that these connections wear and don't maintain a constant connection.  Move the ignition assembly in the right (or wrong) way and connection to ignition is lost.

It isn't a 'loose wire' as such, although a loose wire can easily be identified once the plastic surround is removed.
Title: Re: Imobiliser key "chip" question.
Post by: zirk on 02 January 2013, 21:26:35
Had to change a ECU, Transponder Loop and Key set for the same reason a few years back on a 2000 MV6.

Everything was as it should be on the old stuff, connections all firm etc, is I was to hazard a guess think I would put it down to a signalling issue probably a dry joint on the Transponder Loop Circuit Board.

 :-\ :-\
Title: Re: Imobiliser key "chip" question.
Post by: Big_Al on 02 January 2013, 21:30:47
Ok . .  thanks for that info .

I will leave it until the weekend to see if any more non starting or cutting out occurs and will then have a bit of exploration around the

barrel area in daylight.

If no more breakdowns i will just leave as is  :y :y :y