2000 pontaic grand am 2.4L

thank u what does it do the body control can it cause engine not to spark

The BCM is either connected to or controls nearly every function of the vehicle, and there is one way that it can cause a no-spark. If the anti-theft immobilizer tells the BCM that it does not recognize the key, the BCM will tell the engine control module, and the engine control module (which controls every aspect of engine control systems) will disable the engine. The disabling method may be cutting fuel, power to injectors, ignition system (spark), or a combination.

thank u for that information 1 more question every time I turn the ignition on its ok but when I turn it before turning motor over it blows the 10 amp fuse under the hood that says pcm & ingnition fuse 10 amp also ignition switch has been rsplaced can it be pcm computer

That's pretty beat, I'll look at the schematic and see. In the mean time, when was the ignition replaced? Did it ever work?

we put the ignition switch in about a month ago brand new that's not all I replaced the spark plugs & new control module & both coil packs & cam sensor & another sensor ...securtity light stays on no blinking when turning engine over it blows the 10 amp fuse under hood pcm & ignition might be short to ground on that 10 amp fuse...done everything no sound of fuel pump I believe if I can stop it from blowing fuel pump & injectors will come back...help

please let me know what u think I'm also fighting als disease

also the ignition switch has been replaced I got new keys & tumbler to go in it...did not use that part yet the tumbler with new keys yet becase I know I need to use the old tumbler and keys first once its running again with spark I ca change it out then for the re learn process

Which ignition switch fuse is blowing? There are a couple that should be labeled IGN-SW plus a number.

I'm leaning on the ignition switch and wiring harness right now. The switch may be shorted inside, or the harness may be shorted to ground. Also, the PCM could be causing the fault if it is drawing too much current. However, it is not lost on me that the issue only occurs in the start position, so I'm curious to know if the generator circuit is not playing a part. Testing the resistance across the ignition switch while in the start position may show high impedance.

ok thank,s when u find out more on ignition or harness or computer please keep me updated u have been the best advace yet....and also pray for me I have als disease 2 to 5 years no cure death scott

Sorry to hear that Scott, I don't mind helping at all. Let me know how the ignition switch test goes, and check for any signs of damaged wiring between the ECM and power distribution box.

the fuse box under hood of 2000 pontaic grand am se it,s # 39 pcm & ingntion same fuse for both 10 amp fuse

& what generator

Generator and alternator are interchangeable terms.