I've had this vehicle for only about a year or two;
and over the summer it started to have a problem with starting. Every once and a while i'll attempt to start my Impala and it'll just shut me down.
I've read on many different forums that it could be the Passlock system that's found in GM vehicles from around my car's time.
i'm wondering if anyone has an updated way of fixing the problem, or if i should scrap it and buy a new car, because the inability to start my car before work is bad, but then also not have it start after is even worse.

 

if its a passlock problem the security light should start flashing after trying to start the car.

Which scenario are you getting?

-does it crank over start them stall
-does it crank over but not start
-does it not crank over

 

the security light doesn't come on, but speaking to a couple people, they think that it could be an aftermarket security system..
on my car there's the system where you need to tap on the break to start the car, BUT now i'm wondering why there used to be a ten-minute re-coding or whatever.
but, to answer your question,
*it doesn't crank at all.

 

speeometer does not work show low fuel with full tank check engine lite on wont turn over found one bad 15amp fuse

 

when you turn it to run do all the dash lights come on?
when you turn further to the crank position do you hear a single click from the starter solenoid? have someone listening under the hood.

 

I haven't seen an update, and i know this is an aging thread, but my 2002 Impala LS 3.8 is doing something similar. Passlock has been ruled out. I've narrowed it down to the wire harness that goes to the top of the engine (the one that hangs from the strut brace over the battery). If someone holds the key in start position and I wiggle that wire, it will start. More often now, I just hold the key in start for 10-20 seconds and usually by 3rd try it will start on its own. I haven't had time to take a good look at the connector or the wires but I imagine that if I find out which wire goes to the starter and bridge the connector using some wire taps, I'll not have this problem again.

 

Just an update. After tracing the starter wire from the S post on the starter all the way back to the starter relay (pin 30) , i found the wire to be in excellent shape with no issues. The diagnosis is a bad starter. The wiggling and messing with the connector were just lucky coincidence.