About a year ago I started having issues with my 03 M45 occasionally not starting. Had the crank position sensor replaced a few times, then 13 months ago I had the starter replaced. Lo and behold it started acting up a few weeks ago. Turn the key, single click from the engine bay - all electronics were fine, AC worked, radio, headlights, etc. Wasn't a battery issue. Had the car towed to a local repair shop. They called me a few hours later saying the car started just fine, they couldn't find any problems.

Fast forward to yesterday, car sat in my garage all weekend. Monday morning go to start it - single click. So I call the shop, they say a guy is going to come look at it later in the afternoon. He ended up cancelling, so I got to thinking about what we did the last time - the only thing that was done was the car was locked when I dropped it off - I park it in my garage unlocked.

So I lock the car with the keyfob, unlock it... what do you know, fires up just fine first time.

Has this happened to any of you? In both instances, the car sat unlocked in my garage for the weekend and then wouldn't fire up. This is very odd. Car is in perfect shape mechanically, 139k backroad and highway miles. Sucks I spent over $200 in diagnostics and rental car costs when all I had to do was lock and unlock it. Any input would be much appreciated.

This is new to me and this forum. Thanks for reporting the issue.

I wonder if, when the issue occurs, you can rotate the key to the ON position, hold the brake, move the gear selector to neutral and then start the car. Please attempt and report back.

Actually tried this yesterday morning when it wouldn't start - attempted to start from all gear positions, no such luck. Would not start until I locked the car with the fob and unlocked it.

Assuming it happens again I'll try and document further, I'm guess this is related to the vehicle immobilizer, somehow. Did not notice any odd behavior from the security light, or any other electrics in the car. I've had a check engine light on occasionally over the last few years, but that's apparently related to an evap code that no one in the state of Illinois can seem to actually diagnose or fix and the closest Infiniti dealer wants my first born in exchange for looking at the car.

Initially I would think starter issue with what you described but if the car starts after do'n the lock/unlock move then it may be the factory alarm being armed somehow. Locking/unlocking driver door will reset it and let the veh start. Just a thought, experienced it many times in my line of work.

Six Legs is on to something here. I could be wrong but I believe I read in the manual that if you leave the car unlocked and the key fob is away from the car for a set period of time, the engine kill switch activates and it cannot be deactivated until you lock / unlock the car with the remote. Part of the anti-theft system if I recall.

I know this post is over 6 years old but it helped (unlocking and locking doors).

I have been trying to start my 2004 M45 for the past week with no success. I purchased a new battery and checked fuses .... but I only had success in starting by locking/unlocking the door while trying the ignition.

I was able to move the car to a place and position to further investigate this issue.