Experiencing a security light issue in your Grand Am can be frustrating, especially when you’re trying to diagnose the problem with an OBD scanner. The security light, often related to the Passlock system, is designed to deter theft, but it can sometimes activate unnecessarily or after you’ve performed maintenance. This article will guide you through understanding the security light and how to address it, particularly in situations where you might be using an OBD scanner for diagnostics.
The “security” or “theft system” light in your Pontiac Grand Am is usually linked to the Passlock system. This system is designed to prevent vehicle theft by disabling the fuel system if it detects an unauthorized attempt to start the car. Common scenarios where you might see this light illuminated include:
- Passlock System Issues: The Passlock sensor itself might be malfunctioning, causing the system to incorrectly believe there’s a theft attempt.
- Component Replacement: If you’ve recently replaced components like the Body Control Module (BCM) or Powertrain Control Module (PCM), the security system might need to be relearned to recognize the new parts.
- OBD Scanner Usage: While an OBD scanner itself doesn’t directly cause the security light to come on, you might encounter the light while diagnosing other issues using a scanner. It’s important to differentiate between codes related to the security system and other unrelated diagnostic trouble codes (DTCs).
When your security light is on, your car might not start, or it might start and then stall. Using an OBD scanner in this situation is a good first step to check for any stored DTCs. However, standard OBD scanners might not always read specific Passlock system codes. Even if you don’t find security-related codes, the procedures below can help reset the system.
Here are two key procedures, as outlined in the GM Service Manual, to help you relearn the Passlock system and potentially resolve the security light issue. It’s important to note that these procedures are designed for situations where components have been replaced or the system needs to be reset.
10-Minute Learn Procedure (Tech 2 Recommended)
This procedure is more technical and ideally uses a Tech 2 scan tool, which is a professional-grade diagnostic tool used by GM technicians. While the original manual mentions a Techline terminal, for most DIYers and smaller shops, the Tech 2 is the more relevant tool if specialized equipment is used.
- Tech 2 Connection: Connect a Tech 2 scan tool to your Grand Am’s OBD-II port.
- Service Programming Request: Navigate the Tech 2 menu to “Service Programming” and select “Request Information.”
- Techline Terminal (If Applicable): Disconnect the Tech 2 from the car and connect it to a Techline terminal if the Tech 2 requires online access for this function (this step is less common now with updated Tech 2 software).
- Theft Module Re-Learn: On the Techline terminal (or directly on the Tech 2 if capable), select “Theft Module Re-Learn” under “Service Programming.”
- Reconnect to Vehicle: Disconnect from the Techline terminal (if used) and reconnect the Tech 2 to your Grand Am.
- Ignition ON: Turn the ignition key to the “ON” position, but do not start the engine.
- VTD Re-Learn: On the Tech 2, select “VTD Re-Learn” (Vehicle Theft Deterrent Re-Learn) under “Service Programming.”
- Attempt Start & Observe Security Light: Try to start the engine (it will likely not start). Release the key back to the “ON” position. Observe the security light on your dashboard.
- Wait for Security Light to Turn Off: Wait for approximately 10 minutes. The security light should turn OFF. This indicates the system is ready to relearn.
- Ignition OFF/ON Cycle: Turn the ignition OFF for 5 seconds, then turn it back ON.
- Start Engine: Start the engine. The vehicle should now have learned the Passlock password.
- Clear DTCs: Use the Tech 2 or a capable OBD scanner to clear any Diagnostic Trouble Codes (DTCs).
30-Minute Learn Procedure (No Special Tools Required)
This procedure is simpler and doesn’t require specialized tools, making it accessible for most owners.
- Ignition ON: Turn the ignition key to the “ON” position, without starting the engine.
- Attempt Start & Observe Security Light: Try to start the engine (it will not start). Release the key back to the “ON” position. Observe the security light.
- Wait for 10 Minutes: Wait for approximately 10 minutes until the security light turns OFF.
- Ignition OFF/Wait: Turn the ignition OFF and wait for 5 seconds.
- Repeat Cycle: Repeat steps 1 through 4 two more times. This will complete a total of 3 cycles, taking about 30 minutes.
- Start Engine: After the third cycle, start the engine. The system should now have relearned the necessary data.
- Clear DTCs (Optional): You can use an OBD scanner to clear any DTCs if you have one. History DTCs will clear themselves after about 100 ignition cycles.
Important Notes:
- BCM Programming: Before attempting these learn procedures, ensure your BCM is correctly programmed with the right RPO (Regular Production Option) configurations, especially if it has been replaced.
- Professional Assistance: If these procedures don’t resolve the security light issue, or if you’re uncomfortable performing them, it’s best to consult a qualified mechanic or a GM dealership. They will have more advanced diagnostic tools and expertise to troubleshoot complex security system problems.
- OBD Scanner for Diagnosis: Remember, while an OBD scanner might not directly reset the Passlock system in all cases, it’s still a valuable tool for reading other engine or system related codes that might be indirectly causing security issues or are present alongside them.
By understanding the Grand Am security light and utilizing these reset procedures, you can often address common issues, especially when they occur after component replacement or when you’re using an OBD scanner to investigate vehicle problems.
