I have an 04 and i dont see my the switch under the master,my car would not start..move shifter around and it started..

 

Take a look where the cable attaches to the transmisison. If there's a black plastic chunk there with a harness connection, that's what outputs what gear its in.

If there is no electronic module there, then it has the IMS which is internal to the transmission. I know the IMS setup was introduced in ~99 on the 4t65, but they were hit and miss with rollout. Worked on a 03 GP once that still had the external module, so I'm not sure what the 04 monte got.

 

mine dont have anything under there,i see the shaft and the tranny arm.i could not start my car,called AAA and when the guy got there,he did the same thing i did..put it in neutral and it started up..what would have caused it to not start..

 

So it'll have the internal IMS then. Doesn't necessarily mean the transmission needs to come apart if it broke though - people have done the conversion to external for swaps and such.

Not sure if the IMS is actually causing the issue though- you'd have to get the wiring diagram and check the appropriate wire outputs from the transmission plug.

 

I saw on a site 2004 didnt have that internal IMS ..hmm

 

AFAIK there's only two options on the 4t65, external (on top of the transmission) or internal (inside the transmission). If you think its somewhere else, you'll have to take a look at the wiring diagram for your car to see where it shows it being located.

 

Both of my 02 Monte Carlos are internal. My switch is bad in one of them. My tranny harness plug is green. What I have found on Pontiac is their plug color is red and wires are different colors. What I need is the wires on my green plug to tap into to convert to a external neutral safety switch. Does any one have that diagram?