Hi, I've been driving my old GS300 without problems for ages, but suddenly when I turn the key to start it all I get is a click. this happens about half the time. I first suspected the alternator, so tested it and the bettery. Ther battery hold a good charge and the alternator supplies a steady and healthy voltage when I measure its output while in idle. So now I'm wondering if its the immobilizer system at fault. Up to now I have always been able to get the car to start eventually. Usually when the fault occours it only clicks, then after a few attempts to start there is a sluggish turnover which halts. then after another one or two attempts the sluggish turnover gradually picks up speed and the car starts. I get the feeling that if I hold the key close to the start position but not quite, for a few seconds I can get the car to turn over more rapidly once I go to the start position. The other thing is, if I stop and restart the car sometimes its start no problem and sometime it goes through the clicking and nonstarting routine. Is there a simple way to defeat the immobilizer or bypass it somehow to test if it is in fact that thats the issue..? Anyway I hope someone can come up with some insight. Many thanks in advance.

welcome to the club

Sounds like the solenoid on your starter motor. I have a link in my signature to a tutorial that I did for overhauling the solenoid.

[quote name='Neopyrrhus' date='30 July 2010 - 05:21 AM' timestamp='1280496104' post='727984']
Hi, I've been driving my old GS300 without problems for ages, but suddenly when I turn the key to start it all I get is a click. this happens about half the time. I first suspected the alternator, so tested it and the bettery. Ther battery hold a good charge and the alternator supplies a steady and healthy voltage when I measure its output while in idle. So now I'm wondering if its the immobilizer system at fault. Up to now I have always been able to get the car to start eventually. Usually when the fault occours it only clicks, then after a few attempts to start there is a sluggish turnover which halts. then after another one or two attempts the sluggish turnover gradually picks up speed and the car starts. I get the feeling that if I hold the key close to the start position but not quite, for a few seconds I can get the car to turn over more rapidly once I go to the start position. The other thing is, if I stop and restart the car sometimes its start no problem and sometime it goes through the clicking and nonstarting routine. Is there a simple way to defeat the immobilizer or bypass it somehow to test if it is in fact that thats the issue..? Anyway I hope someone can come up with some insight. Many thanks in advance.
[/quote]

get your starter motor repaired.if fault persist contact your dealer........