Wont turn over first try

[f_vos]

This problem is getting worse.
Go to start the car and turn the key and the motor wont turn over.
Dash light etc on ok but second turn of the key and she turns over and starts as normal.
Seems to be only when the car is hot and parked for 5min then one goes to restart that it wont turn over the engine.
155,000km on the clock and otherwise runs like a dream.
Not sure if I should dissconnect battery to reset ecu.

Any ideas please.

Regards

 

[f_vos]

Also this is when leaving the car unlocked so maybe it relates to the key?

 

[CONROD]

Had the same thing happen in a VY ute I used to have!!!
Jumped in one morning to go to work,it unlocked as normal,but refused to turn over.As the wife worked 5 mins up the road she came back with the second key,gave it another go,and it kicked straight over.
Turned out to be the battery in the key.
Try this next time it does it, does your flashing security light go out or does it continue to flash when you turn the ignition on to light up your dash for it to do its check ?
Alot of people say the battery in the key head gets charged when the key touches the surround on the ignition ring,thats a myth.
Its your battery in your key head telling you to replace it.
I paid $120 for a replacement from Holden,that was about 6-7 years ago,sure you might save a couple of bucks getting a key cutter to do it ,but if thats your original and its lasted over 7 years would you really bother trying to skimp on a few bucks and have issues with the key down the track.
Oneother thing the fellas at Holden told me,when your battery is dying and if the security light continues to flash when you go to crank the engine press and hold down the unlock button as the immobiliser needs to be turned off before the starter motor recieves a signal to crank over,
Just my two bobs worth,hope it helps you out mate
Cheers CONROD

 

[f_vos]

Thanks I will look in the morning as the car is never locked overnight.
If it means a new key from holden then its a simple job.
Regards