Customer Inquiry: Hello! I’m looking for detailed information about using a GM Tech 2 scanner for my vehicle. I may need to perform a BCM (Body Control Module) relearn, and I’m unsure about the software version or programming requirements involved. There are a lot of options online—refurbished and imitation units—and I want to make sure I get a reliable setup that will work properly. Thank you.
Chevy Mechanic Response: Thanks for your question! With years of experience working on GM vehicles, I can help clarify things.
To perform most tasks, including BCM relearn, you will need a Tech 2 scanner loaded with software version 33.004 or later. However, it’s important to note that while the Tech 2 can perform functions like theft deterrent relearn and module synchronization via the “Body Control Module > Special Functions” menu, it does not handle programming or flashing of modules.
For programming tasks such as flashing a new or replacement BCM, you’ll need:
- A laptop with TIS2000 software installed
- A USB-to-RS232 adapter to connect your Tech 2 to the laptop
Further Customer Details: Thanks, that clears up a lot. I think I might be dealing with a Passlock or BCM issue. My truck starts but dies after a few seconds, and the anti-theft light turns on and stays lit. I’ve attempted multiple key relearns with no success. Also, I’m noticing strange electrical behavior inside the cab.
Mechanic’s Diagnosis: Yes, that certainly sounds like a BCM or Passlock issue—especially with the theft light remaining illuminated and the engine shutting off on a consistent timer. Since you’ve confirmed that fuel delivery is fine (good fuel rail pressure), the issue likely lies in a lack of communication or synchronization between the BCM and ECM.
Here are a few steps to take:
- Inspect the BCM power and ground connections, especially beneath the dash. Clean and tighten any corroded or loose connections.
- Use the Tech 2 to check for B-class codes. Faulty BCMs may not always set theft-specific codes but can log other body-related electrical errors.
- Before replacing any components, try disconnecting the battery for 30 minutes, then attempt the 30-minute key relearn procedure again.
If the theft light stays on after that, it’s very likely the BCM is faulty and needs to be replaced and reprogrammed.
Final Customer Question: Thanks again! If I decide to buy a Tech 2 scanner, will I still be able to get the TIS2000 software and use it for BCM programming?
Mechanic’s Answer: Yes, you can still obtain TIS2000, though it may require some searching since it’s no longer officially supported. Just make sure the Tech 2 you purchase includes the necessary hardware and that you also get a compatible USB-to-RS232 adapter. With this setup, you’ll be able to perform both diagnostic and programming functions properly.