I've been working on a 2000 century that a customer put an ecm in and it'* not getting a start signal to crank...to keep the post short heres the lowdown:
There is no fuel enable wire coming from the pcm..
I traced the wires from the key and there is no vats module...they go to the bcm.
Is the dark blu wire on the bcm the fuel enable? I hooked up 50hz to that wire and pump still cuts off. Does this mean I need 30hz?
Anyone know why pin 70 says dk blu fuel enable but it'* not there it'* got a factor plug in it like the other not used ones.
Anyone have the bcm pinout and is the dk blue in the corner the fuel enable?

I should add that the security light on left if dash lights up and turns off. I jump the starter and it runs and shuts off.

What does the scan tool show during cranking?

It doesnt crank with the key. The ignition has already been replaced and I put a resistor of correct value in for good measure.
You can get an idea of vats status by the light but this one just comes on and goes off like normal and even if i disconnect the key sense wont do anything ot should like flash or stay on.
I can jump the starter and it runs and dies. I looked for the fuel enable wire on the pcm but there isnt one.
The key wires go directly to the bcm. I cant find a diagram for the 2000 but there is one dk blu wire so must be it. I tried 50hz but didnt work I'll try 30 tomorrow.

So this car sat for a year or so and wouldnt start...guy arbitrarily replaced the starter and fuel pump and ecm.
There is no crank so I suspected the vats....but the security light on the left side of dash comes on then goes off. I pulled the plug on the key connector to see if security would flash or be solid....same just came on and off like normal.
Only one obd code for a crankshaft unable to relearn or something....which makes sense with new ecm flashed to vin and cant start yet to relearn.
So I jumped the starter and itll start and then stop.
Seems like a fuel enable problem....
This is where it gets interesting....
Looked on pin 70 of blu ecm connector for the fuel enable wire....its not there...theres never been one on the pcm all the spots it should be are factory plugged on the connector with weather resistant nubs.
So I tore the whole dash apart and couldnt find a vats module ...so I traced the key sense wires and they went to the bcm....
Checked the bcm wiring and no fuel enable signal wire....
So I went to a friends shop and pulled up alldata and got the security diagram....
It says the same as I found visually....there is no vats module nor a fuel enable wire!
From the diagram you can see the starter disable is easily defeated by grounding the yel/blk starter enable wire and cutting the pink from the relay and connect to the ppl crank signal fuse. Easy and tidy.
Hooking the starter like any other car using the closest wires way easier than other methods or running remote wires.
Also why is there no mention of no circuit 229 theft deterrent fuel enable on any vats?
Here is the diagram from alldata.
Am I missing something??

2000 buick century security diagram

Merged two threads for the same issue. Post #5 came from the beginning of a new thread from the same user for the same issue.

Please do not start multiple threads for the same issue.