Hello Fellas! So glad for this Forum and folks like you all. Ok so I have a 2015 XL that:
* 1 month ago would not crank/ not start until you turned the key in ignition 3-5 times (all lights in dashboard and radio would come on/ headlights fine... no noises... just silent but wouldn't crank/start)
* 2 weeks ago when you turned the key, the starter made a grinding noise for about 2 seconds then it would start fine
* Took it to Dealer, did The Works oil change (battery was rated excellent) and asked about recalls pertaining to this issue.. service advisor said none existed and that my issue sounded like I needed to replace starter
* Took it to my mechanic and replaced starter, checked the flywheel for damage (none), cleaned battery terminal and cables....after install....no more grinding noise and seemed to be working fine as truck cranked/started fine for one day
* The next day (yesterday), the truck is back to square one... no crank/no start/ no noises .... just doesn't do anything even after trying to start it 10-12 times

We are so confused and tired of this that I said... I know you all will point us in the right direction... we have only driven the truck 56K miles and don't know what it could be... any ideas fellas? Thanks in advance for your tips!

 

I would suspect the DTRS (neutral safety switch). While holding the key to the Start position, run the selector through the gears slowly and see if catches.

 

Thank you for the tip! How would I test the neutral safety switch to see if its defective? I went outside last night and the truck started just fine? It's a hit or miss thing and its frustrating... is there a tool or computer/method to test the neutral safety switch?

 

There is an alignment procedure for it. Next time it doesn't start, put it in neutral, wiggling the lever till it catches. Not only is it a neutral safety switch, it tells the computer what position you have selected.

 

On the 15s, I assume you have to have the brake pedal depressed? Check the brake switch. Just wagging here.

 

It's not a remote start... I never press on the brake pedal to start it... I just insert the key, turn the key and start it. I will try next time with brake pedal pressed?

 

From your owner's manual:

Vehicles with an Ignition Key
Note: Do not touch the accelerator pedal.

1. Fully depress the brake pedal.

1. Turn the key to start the engine. Release the key when the engine starts.

 

Some new vehicles require the brake pedal to be depressed before it will start such as my wife's 2013 Infiniti. Maybe yours is not that way. Don't know.