Here's why:
* NSS Function: The NSS is a crucial safety device that prevents the engine from starting unless the transmission is in Park (P) or Neutral (N). It's a switch that sends a signal to the ignition system. If the switch is faulty or its linkage is worn, it may not register the correct position, thus preventing the starter from engaging.
* Jamming the Shifter: By forcefully moving the shifter, you're likely temporarily correcting the faulty contact within the NSS or its linkage. This forces the switch to make the necessary connection to signal "Park" or "Neutral."
* Other Possibilities (less likely): While less probable, other issues *could* contribute, but they are usually accompanied by other symptoms:
* Worn shifter linkage: This can lead to imprecise shifting and might exacerbate the NSS problem.
* Faulty ignition switch: This is less likely as the problem is specifically linked to the shifter. A faulty ignition switch would usually cause broader starting problems.
* Low voltage/Battery Issues: A weak battery could make starting difficult and might make a marginal NSS problem worse, but this is typically signaled by other issues like slow cranking.
In summary: The most probable culprit is a failing Neutral Safety Switch. Replacing it is a relatively inexpensive and straightforward repair for a mechanic, though it might be possible for a DIYer with some mechanical aptitude. Inspecting the shifter linkage for wear and play is also a good idea while you're addressing the problem.
