Engine fails to start -- possible short?

[circut]

Hey guys. My 2002 z28 has been giving me quite a few problems lately. First my power window motor goes out, then differential gets shot, and now the engine wont start.

The first 2 problems I believe I have a solution for, however I cannot seem to figure out how the engine fails to start. When I put my key in (tried 2 different keys) all the dash lights and everything come on, but when i go to turn the key, everything goes dead. It's almost like the clutch isnt engaged or something...

I've read quite a few posts talking about the VATS system on this car going bad. There were 62k miles on the car, so this may be the problem. I'll be sticking a resistor in it today to find out if the bypass will work.

Are there any other things I might try to determine why the engine will not start?


Also, when my dad and I were looking it at, we noticed that when you rub the battery wire which connects to the fuse boxes, there are sparks.. He was saying that its because of a short somewhere in the electric system. But if there was truly a short, after a week of sitting, the battery surely would have gone dead. I'm wondering if it sparks because of the clock or radio or VATS system or something..

Has anyone heard anything like this before? And might someone provide me a link to the wiring diagrams for the 2002 z28 6-spd manual?

Thanks a million guys,

-Erik

[Christopherrr]

Security Light on after your failed start? If it does come on it indicates VATS was tripped. Turn your car on and make sure all your LED indicators light up...just letting you know so you can make sure your "security" indicator works.

Now when you say, "goes dead" do you mean everything turns off? VATS won't "kill" the car, just keeps it from starting...everything stays on.

[esoteric]

Sounds like you got a bad ground, you turn the key and all the lights go out and the radio cuts off completely? Are you sure the battery is good? Its charged? This is usually a sign of a bad battery too. Just because a battery plays your stereo does not mean its good.

I just had a Positive cable go bad on my 70 Cutlass, a bit older but still that was weird (1st for me). But I have heard that the ground on newer cars seems to wear through and actually become detatched. Check that your gound is good.

Got an Ohm/volt Meter? if not get one. It will help you a lot troubleshooting these type of issues.

Hope this babbling helps somewhat.

[fastTa]

Hey guys. My 2002 z28 has been giving me quite a few problems lately. First my power window motor goes out, then differential gets shot, and now the engine wont start.

The first 2 problems I believe I have a solution for, however I cannot seem to figure out how the engine fails to start. When I put my key in (tried 2 different keys) all the dash lights and everything come on, but when i go to turn the key, everything goes dead. It's almost like the clutch isnt engaged or something...

I've read quite a few posts talking about the VATS system on this car going bad. There were 62k miles on the car, so this may be the problem. I'll be sticking a resistor in it today to find out if the bypass will work.

Are there any other things I might try to determine why the engine will not start?


Also, when my dad and I were looking it at, we noticed that when you rub the battery wire which connects to the fuse boxes, there are sparks.. He was saying that its because of a short somewhere in the electric system. But if there was truly a short, after a week of sitting, the battery surely would have gone dead. I'm wondering if it sparks because of the clock or radio or VATS system or something..

Has anyone heard anything like this before? And might someone provide me a link to the wiring diagrams for the 2002 z28 6-spd manual?

Thanks a million guys,

-Erik

Are you talking about the postive distribution block mounted on the front of the shock tower behind the battery where you are seeing sparks? Nevertheless, sparks are not a good thing and that is a problem. It sounds like you may have a damaged wire or a loose connection. That could definitely not allow enough current to get to the starter.

[circut]

When I put the key in and turn it to the on position, all the dash lights come on, the radio plays and everything seems fine.. But when I go to turn the key to turn the engine on, all the lights turn off, the headlights go out and the 'security' and 'service engine soon' lights stay on..

Like I said, when my dad an I were testing the fuses by pulling one, and checking the battery to see if there were sparks when we rubbed the battery wire on this screw by the fuse boxes, there were small sparks each time..

If this is a grounding issue, where the heck do I begin to look for this short at? The only thing I can think of is possibly the speaker or window motor. The window motor was giving me problems when I parked the car in the driveway. And the speaker has been cracking for ahwile now.

I'll be looking at this later today, so any help you can give me is GREATLY appreciated..

Thanks for the tips guys, I hope it is a ground issue because I cant afford a new key cylinder from GM.

-Erik

[circut]

Are you talking about the postive distribution block mounted on the front of the shock tower behind the battery where you are seeing sparks? Nevertheless, sparks are not a good thing and that is a problem. It sounds like you may have a damaged wire or a loose connection. That could definitely not allow enough current to get to the starter.

Yes, this is the screw which is by the 2 little fuse boxes in the engine area on the righthand side. Should I be seeing sparks there?

-Erik

[fastTa]

Well, you keep referring to a "fuse box." There is a fuse/relay box in the front/driver's side of the engine bay, but I think you must be referring to the postive junction block (the red plastic thing with the big "plus" sign on top).

Then right behind the junction block, is a ground junction with 2 wires being grounded to the front of the passenger side shock tower.

In either case, whether you were touching the negative battery cable to the postive junction block (the red thing) or touching the postive battery cable to the ground, of course you are going to see sparks. You are completing a relatively high amperage circuit.

I'm not sure why you were even doing that. That's a good way to screw up the fusible links and/or PCM.

How is the condition of the starter and/or starter wires?

[circut]

Well, you keep referring to a "fuse box." There is a fuse/relay box in the front/driver's side of the engine bay, but I think you must be referring to the postive junction block (the red plastic thing with the big "plus" sign on top).

Then right behind the junction block, is a ground junction with 2 wires being grounded to the front of the passenger side shock tower.

In either case, whether you were touching the negative battery cable to the postive junction block (the red thing) or touching the postive battery cable to the ground, of course you are going to see sparks. You are completing a relatively high amperage circuit.

I'm not sure why you were even doing that. That's a good way to screw up the fusible links and/or PCM.

How is the condition of the starter and/or starter wires?

I guess were talking about the right thing. There are 2 little boxes which contain fuses for the starter / radio / fans etc.. There is a red wire which appears to run from the battery into these boxes. My dad doesn't know anymore about the car then I do, but he thought the battery was dead so he unhooked the red wire which is connected to the + battery terminal, but he hooked it back up, there were sparks....

Seemed a bit odd to me at the time, but I figured being an electrical engineer I should prolly listen to what he was saying.. I don't think there is a short in it though, because it's been sitting in my driveway for about 2 weeks now and the battery still appears to be fully charged. We also tried to jump it, but again, when I turn the key to start the engine everything but the 'service engine soon' and 'security' lights go out.

The started wires I believe to be fine, I'll inspect when I get home today.

It's the 'security' light which really worries me though. Because when I first got the car, I had the same problem in a parking lot. I put the key in, all the lights and everything came on, but when I turned the key, nothing happend. I fixed the problem by pushing on the little piece of metal thats inside of the key. Once it was re-adjusted, everything worked fine.

But I've tried to test this theory with 2 different keys, and the same thing happens with both. I read something about a resister that you can put somewhere in the ignition to effectively disable the VATS system. I'll be trying that today as well.

-Erik

[Kevin - Blown 95 TA]

You can haev enough of a connection to play radio, lights ec, but starting the car takes a lot more current, so the guys are probably right - a main cable or ground is making poor contact and/or bad starter/engine ground or starter connection or a bad battery cable. If they look corrodd at all, replace them.

[Trans Am]

isnt the security light supposed to go out even if the engine doesnt start? I think that if the light stays on there is a VATS problem. does the engine even turn?

[circut]

isnt the security light supposed to go out even if the engine doesnt start? I think that if the light stays on there is a VATS problem. does the engine even turn?

Nope, the engine doesn't even turn. Started doesn't sound like its doing anything either.

-Erik

[Trans Am]

if it doesnt do anything when you turn the key, not even a click from the starter and the battery is charged you most likely have a vats problem. you can bypass it , you can find how if you do a search
good luck

[fastTa]

An actual short circuit doesn't always necessarily lend itself to a situation in which drains the battery. Both an open and short circuit can cause sparks if you have a damaged wire or cable.

It is very common for sparks to jump from the battery cable terminal to the battery post when you are re-connecting the battery cable. Not much electrical potential differential, but a substantial amount of current available.

But, it sounds like a VATS problem to me as well now. Get your car on a scanner and find out if there are any VATS related codes present.

[circut]

So there is no way to manually reset the VATS system? I read somewhere that there is a way to reset it in certain models of the camaro.. But I don't think it affects my particular year..

Come to think of it, I actually read it in the camaro service manual I bought... I'll try it out too.

Thanks again for your help guys!

-Erik

[fastTa]

If it failed to correctly read the key or if the key was dirty and prevented the proper resistance from being measured within the lock cylinder, the BCM will automatically allow another try after 3 minutes. The BCM (body control module) is programmed to expect a specific resistance which is associated with a key number.

Try cleaning the resistor pellet on each of the keys with some rubbing alcohol. Dirt can prevent them from being read correctly.

Pulling the PCM fuse will clear any non-stored codes, including all the PASS KEY related codes, but it will not manually "reset" the PASS KEY system.

Like I said above, you really should get it scanned to rule out any PASS KEY mechanical or electrical failures which there are codes for.