For 1990-2009 cars

This table identifies which serial data link that a particular module uses for in-vehicle data transmission. Some modules may use more than one data link to communicate. Some modules may have multiple communication circuits passing through them without actively communicating on that data link. This table is used to assist in correcting a communication malfunction. For the description and operation of these serial data communication circuits refer to Data Link Communications Description and OperationData Link Communications Description and Operation.

Control Module | Data Link Type | Diagnostic Procedure
--- | --- | ---
Schematic Reference: Data Communication Schematics.
Automatic Headlamp Levelling Control Module | High Speed GMLAN | Scan Tool Does Not Communicate with High Speed GMLAN Device
Bluetooth Module | Non-GMLAN | --
Body Control Module (BCM) |

• | High Speed GMLAN

• | Low Speed GMLAN

Scan Tool Does Not Communicate with High Speed GMLAN Device

Electronic Brake Control Module (EBCM) | High Speed GMLAN | Scan Tool Does Not Communicate with High Speed GMLAN Device
Electronic Suspension Control Module | High Speed GMLAN | Scan Tool Does Not Communicate with High Speed GMLAN Device
Engine Control Module (ECM) | High Speed GMLAN | Scan Tool Does Not Communicate with High Speed GMLAN Device
HVAC Control Module | Low Speed GMLAN | Scan Tool Does Not Communicate with Low Speed GMLAN Device
Inflatable Restraint Sensing and Diagnostic Module (SDM) | Low Speed GMLAN | Scan Tool Does Not Communicate with Low Speed GMLAN Device
Instrument Panel Cluster (IPC) | Low Speed GMLAN | Scan Tool Does Not Communicate with Low Speed GMLAN Device
Memory Mirror Module | Non-GMLAN | --
Memory Seat Module (MSM) | Non-GMLAN | --
Navigation Unit | Non-GMLAN | --
Navigation Interface Module | Low Speed GMLAN | Scan Tool Does Not Communicate with Low Speed GMLAN Device
Object Alarm Module | Low Speed GMLAN | Scan Tool Does Not Communicate with Low Speed GMLAN Device
Rear Seat Entertainment Interface Module | Low Speed GMLAN | Scan Tool Does Not Communicate with Low Speed GMLAN Device
Remote Function Actuator (RFA) | Low Speed GMLAN | Scan Tool Does Not Communicate with Low Speed GMLAN Device
Secondary Information Centre | Low Speed GMLAN | Scan Tool Does Not Communicate with Low Speed GMLAN Device
Seat Interface Module | Low Speed GMLAN | Scan Tool Does Not Communicate with Low Speed GMLAN Device
Steering Angle Sensor | High Speed GMLAN | Scan Tool Does Not Communicate with High Speed GMLAN Device
Theft Deterrent Control Module | Low Speed GMLAN | Scan Tool Does Not Communicate with Low Speed GMLAN Device
Transmission Control Module (TCM) | High Speed GMLAN | Scan Tool Does Not Communicate with High Speed GMLAN Device
Telematics Module | Low Speed GMLAN | Scan Tool Does Not Communicate with Low Speed GMLAN Device