The Bosch Tech 2 scan tool is a powerful diagnostic tool for various GM vehicles. However, understanding its compatibility with different model years, specifically regarding the Class 2 and CAN networks, is crucial. This article clarifies the Tech 2’s functionality with 2004-2006 GM models, focusing on communication protocols and module accessibility.
Understanding Class 2 and CAN Networks in GM Vehicles
GM vehicles from 2004 onwards utilize two primary communication networks: Class 2 and Controller Area Network (CAN). The Class 2 network connects most modules, while the CAN network is primarily for the Engine Control Module (ECM) and Transmission Control Module (TCM) in newer models (2005-2006). The Bosch Tech 2 interacts with these networks differently.
Tech 2 Compatibility with 2004 Models
In 2004 models, relying solely on the Class 2 network, the Tech 2 connects through terminal #2 of the Data Link Connector (DLC). This connection allows communication with all modules on this network, including the Remote Keyless Entry module. However, removing the “comb” (a specific connector within the DLC) disables communication with all modules, as it severs the Class 2 connection.
Tech 2 Compatibility with 2005-2006 Models
2005 and 2006 models introduce the CAN network for ECM and TCM communication. The Tech 2 requires a “CANdi” adapter to interact with these modules via pins 6 and 14 of the DLC. Even with the “comb” removed, the Tech 2 can still access the ECM and TCM using the CANdi adapter. However, access to other modules on the Class 2 network remains blocked. The CANdi adapter’s LED indicates communication status: flashing signifies active communication with CAN modules, while a solid LED indicates no communication.
Diagnostic System Test Availability
Initially, there was confusion regarding the availability of the diagnostic system test on 2005-2006 models. This test, relying on Class 2 communication, was thought to be absent. However, it has been confirmed that the diagnostic circuit check is available on 2005 models, though its functionality on 2006 models remains unclear. The message monitor and DTC check, primarily for the Class 2 network, may not display information for the ECM and TCM on these newer models.
Ensuring Proper Tech 2 Functionality
If encountering communication issues with a 2005 or 2006 GM vehicle, verify the following:
- CANdi Adapter: Ensure the CANdi adapter is properly connected for accessing the ECM and TCM.
- LED Status: Observe the CANdi adapter’s LED. A flashing LED indicates proper communication.
In conclusion, understanding the communication protocols and using the correct adapter is vital for successful diagnostics with the Bosch Tech 2 scan tool on different GM model years. While the tool offers comprehensive functionality across various models, the introduction of the CAN network in 2005-2006 necessitates the use of the CANdi adapter for complete module access.
