Bi-polar grand am. New/different symptoms everyday

[Caseyb1983]

Hello all! I have a 99 grand am se V6. For 3 years I have had zero problems. Last week sitting at a light it just turns off but starts right back up. No warning lights at all. I driver her the rest of the way home with no problems except it felt like she was trying to stall a little. The next day the mechanic comes to drive it and after looking it over and saying nothing is wrong it finally died on him too this time not starting back up. He said he has no idea. No codes, fuel pump and pressure is working, battery is fine and it's getting spark. It has a half tank of gas.

So after reading a bit on here I think it's security related so I do the relearn. It started up but rough idle. Like the motor was trying to jump out so I figured it started by chance. Next day it wouldn't start again. Not even after relearn so I tried locking and unlocking doors like I read on here. She started. Drive her around for about 10 mins, parked and turned her off. Next day she wouldn't start for anything. It turns over but never turns on.

The key had been hard to turn for a year now so I went today and had a new key cut. Now the key turns perfectly but now all I get when I turn it over with either the old or new key is a click. Lights and radio work fine.

When I turn the key to ACC all lights come on dash and go off except security and battery. On the ON position all lights go off except check engine and battery. Although every time she has turned on this past few weeks there was no check engine light. I still get no codes.

Also today when I did the relearn and tried to turn it over the trunk popped open by itself.

Any ideas?

[jdl]

You could have more than one problem? If it won't even crank, check that the battery has a full charge. Go from there.

[Caseyb1983]

Originally Posted by jdl

You could have more than one problem? If it won't even crank, check that the battery has a full charge. Go from there.

The battery was dead. I guess due to the relearn procedure. Now it turns over/cranks like it had been doing prior to the relearn. Just won't start up. I read in the manual that the security light SHOULD be on in the on position if the car isn't on so I'm thinking it's not a security issue.

[gmtech1]

Also today when I did the relearn and tried to turn it over the trunk popped open by itself.


Have seen BCM's cause this excact condition. Inspect the BCM connectors for any water intrusion (green fuzzies).

If so, the BCM need replaced and terminals need replace. The new BCM will need to be "set up" using a scanner.

[thephantom1492]

Originally Posted by Caseyb1983

Last week sitting at a light it just turns off but starts right back up. [...] except it felt like she was trying to stall a little.

Could be: Power issue, crankshaft sensor, BCM/PCM,

Originally Posted by Caseyb1983

The next day the mechanic comes to drive it and after looking it over and saying nothing is wrong it finally died on him. [....] it's getting spark.

Power issue, BCM/PCM

Originally Posted by Caseyb1983

So after reading a bit on here I think it's security related so I do the relearn. It started up but rough idle.

Security completly disable the fuel injectors so do not cause rought idle.
Power issue, BCM/PCM

Originally Posted by Caseyb1983

Next day she wouldn't start for anything. It turns over but never turns on.

THAT could be security related.
I suspect Power issue or bcm/pcm.

Originally Posted by Caseyb1983

Now the key turns perfectly but now all I get when I turn it over with either the old or new key is a click. Lights and radio work fine.

Power issue or starter or shift interlock.

Originally Posted by Caseyb1983

Also today when I did the relearn and tried to turn it over the trunk popped open by itself.

Actually, I got that issue when the ignition switch failed.
Power issue or BCM.

My first step would be to check for proper power, a voltmeter can tell alot, just back probe the fuses, look for abnormal voltage. This is how I identified my bad switch issue. Black probe to any ground (bare metal on the car, like a bolt) and probe the fuses... if you see a big difference between the fuse voltage and the battery voltage (battery should be around 12.5V, at <=11V at the fuse I would be very concerned) then it's sign that there is a bad contact, which would be a relay or a switch. The ignition switch is what switch almost all the current in the car. It have probably 2 ignitions wire and 1 accessory wire, for a total of 3 circuits.

Those 3 circuits are "separated", which explain why you might see some stuff working, and some other do not work.

A bad contact often cause intermittant issues.

My next guess would be oxidation at the BCM and PCM.
The PCM is located under the dash, driver side, on the car side. You can't miss the module.

The bcm is behind the glove box. Still lots of wires.

If you see green or white powder, that's oxidation. Beware that if you want to disconnect the connectors, it's hightly advised to remove the battery negative before doing it. Those computers are pricey, you don't want to kill one due to the power that flow in the wrong way.

[Caseyb1983]

Originally Posted by gmtech1

Also today when I did the relearn and tried to turn it over the trunk popped open by itself.


Have seen BCM's cause this excact condition. Inspect the BCM connectors for any water intrusion (green fuzzies).

If so, the BCM need replaced and terminals need replace. The new BCM will need to be "set up" using a scanner.

Thank you. The trunk opening stopped after we jumped the battery. Now the starter has gone bad. So before we can find out what the original problem is I have to change the starter. The mechanic tapped the starter as I tried to start the car and after a few times she started right up.

[Caseyb1983]

Originally Posted by thephantom1492

Could be: Power issue, crankshaft sensor, BCM/PCM,


Power issue, BCM/PCM


Security completly disable the fuel injectors so do not cause rought idle.
Power issue, BCM/PCM


THAT could be security related.
I suspect Power issue or bcm/pcm.


Power issue or starter or shift interlock.


Actually, I got that issue when the ignition switch failed.
Power issue or BCM.

My first step would be to check for proper power, a voltmeter can tell alot, just back probe the fuses, look for abnormal voltage. This is how I identified my bad switch issue. Black probe to any ground (bare metal on the car, like a bolt) and probe the fuses... if you see a big difference between the fuse voltage and the battery voltage (battery should be around 12.5V, at <=11V at the fuse I would be very concerned) then it's sign that there is a bad contact, which would be a relay or a switch. The ignition switch is what switch almost all the current in the car. It have probably 2 ignitions wire and 1 accessory wire, for a total of 3 circuits.

Those 3 circuits are "separated", which explain why you might see some stuff working, and some other do not work.

A bad contact often cause intermittant issues.

My next guess would be oxidation at the BCM and PCM.
The PCM is located under the dash, driver side, on the car side. You can't miss the module.

The bcm is behind the glove box. Still lots of wires.

If you see green or white powder, that's oxidation. Beware that if you want to disconnect the connectors, it's hightly advised to remove the battery negative before doing it. Those computers are pricey, you don't want to kill one due to the power that flow in the wrong way.

Thank you both. We will be checking this right after he installs the new starter tomorrow.

[Caseyb1983]

This has me aggravated. Somehow the starter went bad. (machanic could get the car to start by tapping starter). We changed that. The car started. Drove it for 15 minutes and it shut down. Wouldn't start. No warning lights on what so ever. Radio and lights all work. A friend jumped the car because he seems to think its the alternator although the machanic says its fine. The car starts but just sputters. Very rough idle. No driving it. Just dies.

I originally thought it was the security but there's no lights and the relearn doesn't help. The car gets spark. The fuel pump is fine. We changed the fuel filter. What in the world could be going on. He doesn't want to change the crankshaft sensor because he said if it was bad the car would NOT get spark.

Just a reminder. The issue started out of nowhere. The car just died at a light but started right back up. Next day it drove for about 15 minutes and shut off. Now it starts at random times and dies after driving 10 to 15 minutes.

[Tech II]

Have a can of carb cleaner handy....when it won't start, spray it into the intake to see if it starts and runs.....if it does, it's fuel related....either no pressure or the injectors are not firing(SECURITY issue).....

[Caseyb1983]

Originally Posted by Tech II

Have a can of carb cleaner handy....when it won't start, spray it into the intake to see if it starts and runs.....if it does, it's fuel related....either no pressure or the injectors are not firing(SECURITY issue).....

He just did that and no go.

[Tech II]

Then you have to check for spark....

[Caseyb1983]

Originally Posted by Tech II

Then you have to check for spark....

It haS had spark since these issues started. He checked again today. He wants to change the alternator this weekend. He thinks that's the problem although no one else does. If this doesn't work then I'm about done.

[thephantom1492]

An alternator is NOT REQUIRED for a car to run.
I've run my car without alternator for a lil while (wire broke during alternator replacement, had to go buy a new connector).

The alternator purpose is to charge the battery, and power the car if enought current is left. If the car crank, it can run.

Now, if it have sparks and fuel pressure... The injector should be monitored for signal to open. Also, it could be that the engine got flooded. To clear the flood, there is 2 ways. The first is counter intuitive: FULLY press the gas pedal then crank... This should put the PCM in clear flood mode, which basically cut the injectors. Crank for like 10-20 seconds, then let the starter cool down for atleast 30 secs, then try to start normally. If that still do not work, remove the spark plugs, remove the fuel pump fuse or relay, crank 10-20 seconds, put back the spark plugs and fuse/relay, try to start. If still not working, it could be an anti-theif issue.

But the fact that your mechanics want to replace the alternator tell me that he's bad, go somewhere else.

[Caseyb1983]

Originally Posted by thephantom1492

An alternator is NOT REQUIRED for a car to run.
I've run my car without alternator for a lil while (wire broke during alternator replacement, had to go buy a new connector).

The alternator purpose is to charge the battery, and power the car if enought current is left. If the car crank, it can run.

Now, if it have sparks and fuel pressure... The injector should be monitored for signal to open. Also, it could be that the engine got flooded. To clear the flood, there is 2 ways. The first is counter intuitive: FULLY press the gas pedal then crank... This should put the PCM in clear flood mode, which basically cut the injectors. Crank for like 10-20 seconds, then let the starter cool down for atleast 30 secs, then try to start normally. If that still do not work, remove the spark plugs, remove the fuel pump fuse or relay, crank 10-20 seconds, put back the spark plugs and fuse/relay, try to start. If still not working, it could be an anti-theif issue.

But the fact that your mechanics want to replace the alternator tell me that he's bad, go somewhere else.

Thank you very much. I will try all these this weekend. AND look for a different mechanic. He said that if while the car is on and you remove the ground wire from the battery and the car dies then it's the alternator. But the car will not stay on long enough to try that. If it starts with a jump it only stays on for a few seconds and dies.

What's confusing is after we changed the starter and gave it a jump it drove for 10 minutes before it died. Then jumped it again and it had a very rough idle but died with in seconds. Twice. I had the battery tested and they said it was fine. The battery light will come on when it dies but everything else in the car works. Radio, lights, battery.......

I appreciate everyone on here. I hope you all realize how helpful and appreciated you are.

[thephantom1492]

Originally Posted by Caseyb1983

He said that if while the car is on and you remove the ground wire from the battery and the car dies then it's the alternator.

Removing the battery wire while the engine run is a good way to kill all the car electronics. NEVER do that!

The alternator is more a current source than a voltage source. What does that mean is that it try to maintain a certain current out. The battery buffer the fluctuation in current and stabilize the voltage. The alternator is slow to react to load change. Removing the battery, so the buffer, will cause the voltage to raise over twice the normal voltage! This is because the alternator output the average current required to power the car. The car use the power in a pulsating manner. No battery = pulsating high voltages.

Something you could do: put a battery charger for a few hours, try to start the car. If the car start, mesure the battery voltage. More than 13V and the alternator work. Less than 12.5V and dropping (possibly slowly) mean that the alternator do not work. But if it can crank, it should be able to start. The starter is what take the most power and require that the battery is the fuller.