Immobiliser problem?

[Ian Hoyle]

My Alphard (early 08) started first time this morning. Ran for 30 mins, stopped engine. Won't start again NOTHING as if immobilised. This has happened on the last three trips: it started first time, ran perfectly, then wouldn't restart at the supermarket/fuel station... until I waited a significant length of time. Then it's as if there was no problem. So it seems like the immobiliser is being triggered somehow. Or could it be a key recognition problem? Anybody recognise this please?

[Tonyatco]

Hi there maybe a problem with your key(s) the battery may not be transmitting enough pulse, try changing the batteries, as well as getting the pulse signal strength checked by an auto technician, another possibility is your car battery needs a good charge giving the immobiliser a stronger receiver 

[Ian Hoyle]

1 hour ago, Tonyatco said:

Hi there maybe a problem with your key(s) the battery may not be transmitting enough pulse, try changing the batteries, as well as getting the pulse signal strength checked by an auto technician, another possibility is your car battery needs a good charge giving the immobiliser a stronger receiver 

Thanks Tony. The key I'm using is a clone, around 1yr old. And the car battery is just months old. I'll refer to the key provider, see what he thinks. Cheers. I.

[dezufo]

22 hours ago, Ian Hoyle said:

My Alphard (early 08) started first time this morning. Ran for 30 mins, stopped engine. Won't start again NOTHING as if immobilised. This has happened on the last three trips: it started first time, ran perfectly, then wouldn't restart at the supermarket/fuel station... until I waited a significant length of time. Then it's as if there was no problem. So it seems like the immobiliser is being triggered somehow. Or could it be a key recognition problem? Anybody recognise this please?

If you have the old style fob with buttons to lock/unlock then the chip in the fob is passive they do not transmit any signal, the chip is read by the circuitry in the ignition, Check the immobiliser indicator, flashing red car shape, if it goes out when you put the key in the ignition then it is working correctly. You could have worn contacts on the starter solenoid or a slightly loose/dirty contact on the battery posts

[Torq2u]

Such helpful advice, as ever. What a great site!

 

[Ian Hoyle]

6 hours ago, dezufo said:

If you have the old style fob with buttons to lock/unlock then the chip in the fob is passive they do not transmit any signal, the chip is read by the circuitry in the ignition, Check the immobiliser indicator, flashing red car shape, if it goes out when you put the key in the ignition then it is working correctly. You could have worn contacts on the starter solenoid or a slightly loose/dirty contact on the battery posts

Thanks, yes the red immob light stays on. Could be the solenoid as you say. When you refer to 'battery posts' you mean the mounts in the key fob, yes? Nothing to do with the car battery?

[dezufo]

29 minutes ago, Ian Hoyle said:

Thanks, yes the red immob light stays on. Could be the solenoid as you say. When you refer to 'battery posts' you mean the mounts in the key fob, yes? Nothing to do with the car battery?

If the immobiliser indicator stays on then the circuit is not reading the chip in the key fob when you put the key in the ignition. So the problem is either in the fob or the ignition circuit. Main battery, the posts can get corroded and thus the voltage drops, the battery in the fob just locks/unlocks the doors