Security light turned on

236,000 MILES • 6 CYL • 2WD • AUTOMATIC
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FUNK1958
  • MEMBER
  • 1 POST
My car's security light is in my message center. my radio shows locked however it will still start and drive, but sometimes the radio wont show locked. when it does show locked my daytime running lights flicker so I have to manually turn on lights and they work. I don't have money to take to shop because I know labor is expensive. any suggestions? I also tried to get code for the radio and it wont pull up. I was told by someone it could be because it is an after market GM key.
May 27, 2019 at 12:39 AM
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STRAILER
  • ✓Experienced Mechanic
  • 55,549 POSTS
Hello,

Both system are controlled by the BCM, I would check the unit and the connector for water damage or corrosion. If you need to replace it here are the instructions with the BCM location below

Introduction

During body control module (BCM) related service, the procedures below are designated to set-up the BCM correctly. Before you start, read these procedures carefully and completely.

Setup New Body Control Module (BCM)

Important: The BCM will not function properly if the Setup New BCM procedure is not performed. Make sure the battery is fully charged before performing the setup procedure. Make sure all disconnected devices and connectors have been reconnected. Perform the Theft Deturrent Re-learn procedure after successfully finishing the Setup New BCM procedure. If the Theft Deterrent Re-learn procedure is not performed after a BCM replacement, the following conditions may occur:
- The vehicle will not be protected against theft by the PASSLOCK system.
- The engine will not crank nor start.

1. Connect a scan tool (Tech 2) to the Data Link Connector (DLC).
2. Turn the ignition switch on.
3. Select Diagnostics and input all of the required data when prompted by the scan tool (Tech 2).
4. Select BODY CONTROL MODULE.
5. Select SPECIAL FUNCTIONS.
6. Select Setup New BCM.
7. Note, Input all of the required data when prompted by the scan tool.
8. Select Setup SDM Part Number in BCM, and follow the onscreen directions.
9. Select New VIN, and follow the onscreen directions.
10. Select Option Configuration, and follow the onscreen directions.
11. Select Point of Sale, and follow the onscreen directions.
12. Exit back to the SPECIAL FUNCTIONS menu.
13. When the BCM, VIN, Point of Sale and Option Configuration have been entered, proceed with the Theft Deterrent Re-Learn procedure.
14. If the scan tool displays UNABLE TO PROGRAM BCM. BCM IS SECURED, then the BCM must be replaced and this procedure must be repeated on a new BCM.

Note: After the above procedure has been completed, personalization of the BCM defaults to a default setting. Inform the customer that the personalization settings must be set again.

Important: After programming, perform the following to avoid future misdiagnosis:
1. Turn the ignition OFF of 10 seconds.
2. Connect the scan tool to the data link connector.
3. Turn the ignition ON with the engine OFF.
4. Use the scan tool in order to retrieve history DTC's from all modules.
5. Clear all history DTC's.

Check out the diagrams (below). Please let us know what you find. We are interested to see what it is.
Mar 17, 2021 at 10:18 AM
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