VS Commodore, key head not starting car

[J.T]

I have a flat battery in the Key Head of my car, Unfortunantly only one key. Took it to locksmiths and there is not enough power in it to read code. I learnt to overide it if I leave key in ignition with accesoriews for 45 mins only prob is this has to be done everytime. Does anyone know if the system can be temporarly be overridden without having to wait 45 mins? Or is there some trick I can do to Key? Can't afford to presentlty have it plugged into diagnostics machine to get BCM security code. I have the Security key code on the security sticker is there another way to find out code so locksmith could reprogram it?
Really appreciate your help, J.T.

[delcowizzid]

fit a new battery in it isnt too hard

[kbelt66]

hi JT
the batt cant be replaced mate sorry.

[delcowizzid]

tell that to all the guys on here who have done it its not direct pull out put one in needs soldering in but is easily doable

[tyrone]

it may be doable but from what ive herd if its gone dead flat or the battery is removed it loses its program so you still in fact have to pay to get it reprogramed so easier to just get a shiney new key head (i could be wrong of course)

[kbelt66]

yep it can be done delcowiz, once you crack the head open cut and prise the battery out of its position
and then solder it backin then superglue everything back together, ( plus make sure all connections are connections).
but why waist all that effort.
just replace the paddlepop, its costs less in the end.

[kbelt66]

no tyrone they do not loose the security code

[moff_man]

try replacing the key reader from around the ignition barrel.

i am lead to believe the battery in the remote is ONLY for the central locking and not for the code. if a $9 key reader doesn't fix the issue than it may be the key it's self but not the battery. i also work at holden and never replaced the remote due to not starting the car.

also remove the stalk from the key and clean the contacts.

what happens is the car sends a small current through the key reader in to the key head and through Resistance and what not down the key stalk to ground (through the ignition barrel) if this docent match the code in the car it wont start. battery in remote is only for central locking and when button is pushed it disarms the security also.


long post but i would try getting a $9 key reader first

[J.T]

What voltage battery does the key head take? I will replace the key head but for curiosity and for a second key I wouldn't mind having a go at trying to replace the battery. Thanks, J.T

[J.T]

Also what is the key reader and where can you get one from?

[J.T]

Hey Moffman, what is the key reader, what does it do (stupid question I know and how) and where can you get one from?

[moff_man]

its the ring looking thing around the ignition barrel it just pops off and there is one wire attached. readily available from holden about $9 trade

[hako]

There is a good how-to in the attached thread. I've replaced batteries twice and did not lose the code, however in both cases the head still had enough power to start the car but not enough to operate the remote.
Replacing the battery in your remote

[Super_Low 91]

the battery does do the central locking an the code,, so if the battery goes completely flat then the key will no longer start the car,,
A commodore key is not like a transponder key. A transponder is a chip that isn powered an gets detected by a field around the ignition barrel where as a commodore transmits its code by direct contact hence the reader around the ignition barrel

[moff_man]

dosnt worry me what you think. i know how the system works and how to fix it.

[Brett_jjj]

Ive got 2 old keys for my VS that will no longer start the car,they have been flat for a couple of years now.They both used to still start the car,they just wouldnt unlock the doors with the remote.Now neither one will even start the car. The battery going completely flat has to have something to do with it.Otherwise they would both still work when in the ignition.When I try to use the 2 old keys,nothing happens when the key is turned to the start position.It doesnt even attempt to crank the engine.I know some key fob security systems use resistance,dont think the holden keys do though.The resistance type security can easily be bypassed with a hand full of different resistors.Theres heaps of websites in the USA explaining how to bypass these systems using the resistors.Ive never heard of anyone doing this with a commodore though.

[moff_man]

if a dealer uses the all new key function it will erase the existing code thus making the old keys unusable, if the battery has gorn flat and the Central locking no longer works than the key is than no longer unuseable anyway. all I'm saying the 2 systems of the key head is different and is earthed through the key stalk. usually the contacts on the stalk get corroded and this making the circuit incomplete.

[Super_Low 91]

they key does not earth in any way what so ever,, the little dome on the key contacts the reader strip on the ignition that is it,, I didn't spend 4 years getting my Locksmith trade an doing almost 2 years of automotive key technology training for nothing, But hey everyone is an expert on this site so i really don't care anymore. I bid you good luck with your boggy half ass battery changing, but also keep this in mind for next time if you pm me i may be able to set you up with a brand new head cheaper then anyone else and guarantee the key to work..

[delcowizzid]

yes and then earths down the key itself to connect the circuit which is connected to the battery inside so it can be coded to the car for it to run

[RX25SE]

As the Commodore is not a transponder type, how does the reader send a signal to the BCM via one wire?

I have seen starting issues in Commodores when the two screws that mount the blade to the head are loose or the contact from the key head to the blade is corroded.

[Brett_jjj]

The code is probably read in serial form,one bit at a time.The system only needs one wire,as its circuit is completed through the earthed key.Also if you have ever had a good look at the PCB in one of these keys,you will see there are 2 contacts,the one that sticks out and touches the key reader,and the other contact tab touches the actual metal part of the key inside near the screw holes for the earthing purposes.Old mate better go back to the locksmith and automotive key technology class and get his money back.

[moff_man]

ive done 8 years of HOLDEN training and 4 of that was a waste of time of an apprenticship. the holdning training i receive is far more better than any tafe or locksmith school can teach. i dont know how manny times locksmith's ib our local area have stuffed up $100 keys and all they say is oh well.

everyone on this site is going to give you diffrent answers, its up to you what you want to do. just remember if you open the key up its never going to be the same again

[scv6]

Ive had commodores "no start". Replaced key head and they start.
Some people treat their keys poorly. Ive seen keys thrown and dropped on concrete, taken swimming at the beach etc etc.

[James39]

just remember if you open the key up its never going to be the same again

Wow, mine worked better than what they did before. But I also resoldered everything as well. that tends to help I feel.