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Greg A
Greg A, Master Troubleshooter
Category: Chevy
Satisfied Customers: 8918
Experience:  Working with Electronics & Cars for 25+ Years
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2003 GMC Envoy Xl: has a steady security light and will not turn over

Customer Question

2003 GMC Envoy Xl has a steady security light and will not turn over. What can I do to fix it?
Submitted: 8 years ago.
Category: Chevy
Expert:  Greg A replied 8 years ago.

Hello & Welcome,


You can try the following procedure to see if you can get the system reprogrammed & be able to start it.




Follow the instructions as carefully as you can, especially the part in Red.


I hope this helps. Please let me know how it goes.


Take Care, Greg A.

Greg A and 4 other Chevy Specialists are ready to help you
Customer: replied 8 years ago.
I tried that and the security light will not go out after 10 minutes. I even let it sit for 15 minutes and it still will not go out. what else is there to do. I've disconnected the battery for now and will go back and reconnect it in a couple of hours.
Expert:  Greg A replied 8 years ago.

Hi again,


The procedure shown assumes that a proper key is being used, that the passkey module (in the ignition area) is working, and that the Body Control Module (BCM), and Powertrain Control Module (PCM) are all working properly.


Any one of these systems could be having problems, and it will most likely take a Tech 2 scan tool (like the dealer uses) to figure out what is happening here. Let me know what happens after you reconnect the battery.


Thanks, XXXXX

Customer: replied 8 years ago.
After reconnecting the battery the security light went out, but it did nothing. This is the second time this has happened since I bought this truck new, but at least this time I can put it in neutral so I can move it.
Expert:  Greg A replied 8 years ago.

So it now does nothing? No attempt to start at all?


Have you had any problems with the battery lately (like running down)?

Customer: replied 8 years ago.
No attempt to start at all. and no I replaced the battery about 7 months ago. Is there any other tricks to get it to start? I'm Air Force and deploying in 3 days and I really need the truck to be up and running for my wife and kids to use.
Expert:  Greg A replied 8 years ago.
So now it will not even turn over the starter motor?
Customer: replied 8 years ago.


Expert:  Greg A replied 8 years ago.

Hmm. It seems like we are going backwards here.


Let me give you the starting system schematic and description of the system.





Starting System Description and Operation

The PG-260L is a non-repairable starter motor. It has pole pieces that are arranged around the armature within the starter housing. When the solenoid windings are energized, the pull-in winding circuit is completed to ground through the starter motor. The hold-in winding circuit is completed to ground through the solenoid. The windings work together magnetically to pull in and hold in the plunger. The plunger moves the shift lever. This action causes the starter drive assembly to rotate on the armature shaft spline as it engages with the flywheel ring gear on the engine. At the same time, the plunger closes the solenoid switch contacts in the starter solenoid. Full battery voltage is then applied directly to the starter motor and it cranks the engine.


As soon as the solenoid switch contacts close, current stops flowing thorough the pull-in winding as battery voltage is now applied to both ends of the windings. The hold-in winding remains energized; its magnetic field is strong enough to hold the plunger, shift lever, starter drive assembly, and solenoid switch contacts in place to continue cranking the engine. When the engine starts, the pinion gear overrun sprag protects the armature from excessive speed until the switch is opened.


When the ignition switch is released from the CRANK position, voltage is removed from the starter solenoid S terminal. Current flows from the motor contacts through both windings to ground at the end of the hold-in winding. However, the direction of the current flow through the pull-in winding is now in the opposite direction of the current flow when the winding was first energized.


The magnetic fields of the pull-in and hold-in windings now oppose one another. This action of the windings, along with the help of the return spring, cause the starter drive assembly to disengage and the solenoid switch contacts to open simultaneously. As soon as the contacts open, the starter motor is turned off.


I would start by checking that crank fuse in the underhood fuse block.


I am also going to try and call in some help as my time will be limited on here after the next couple of hours.


Thanks, XXXXX

Customer: replied 8 years ago.
Ok, thank you. I fully understand schematics and electronics so this is helpful.
Expert:  Greg A replied 8 years ago.

I have already sent a couple of notes to other experts here, so if someone else jumps in, it is because I asked them to.



Customer: replied 8 years ago.
Ok and thanks again.
Expert:  Greg A replied 8 years ago.

No problem.

Let me know what you find on that schematic.