Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Data Link References
This table identifies which serial data link that a particular device uses for in-vehicle data transmission. Some devices may use more than one data link to communicate. Some devices 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. Not all devices listed will be applicable to all vehicles. Refer to the schematics to determine which devices apply. For the description and operation of these serial data communication circuits, refer to Data Link Communications Description and Operation .
| Code | Device | Data Link Type | Diagnostic Procedure |
|---|---|---|---|
| Schematic Reference: Data Communication Wiring Schematics | |||
| A11 | Radio | Low Speed GMLAN | Scan Tool Does Not Communicate with Low Speed GMLAN Device |
| A26 | HVAC Controls | Local Interconnect Network (LIN) | DTC U1500-U15FF |
| B99 | Steering Wheel Angle Sensor | Chassis High Speed GMLAN | Scan Tool Does Not Communicate with Chassis High Speed GMLAN Device |
| B119 | Multi-axis Acceleration Sensor | Chassis High Speed GMLAN | Scan Tool Does Not Communicate with Chassis High Speed GMLAN Device |
| B174W | Frontview Camera - Windshield |
|
|
| B177 | Rain/Ambient Light Sensor Module | Local Interconnect Network (LIN) | DTC U1500-U15FF |
| E13LA | Headlamp Assembly - Left | Local Interconnect Network (LIN) | DTC U1500-U15FF |
| E13RA | Headlamp Assembly - Right | Local Interconnect Network (LIN) | DTC U1500-U15FF |
| K9 | Body Control Module |
|
|
| K17 | Electronic Brake Control Module |
|
|
| K20 | Engine Control Module | High Speed GMLAN | Scan Tool Does Not Communicate with High Speed GMLAN Device |
| K23 | Folding Top Control Module | Low Speed GMLAN | Scan Tool Does Not Communicate with Low Speed GMLAN Device |
| K26 | Headlamp Control Module |
|
|
| K29 | Seat Heating Control Module | Low Speed GMLAN | Scan Tool Does Not Communicate with Low Speed GMLAN Device |
| K33 | HVAC Control Module |
|
|
| K36 | Inflatable Restraint Sensing and Diagnostic Module | Low Speed GMLAN | Scan Tool Does Not Communicate with Low Speed GMLAN Device |
| K38 | Chassis Control Module | High Speed GMLAN | Scan Tool Does Not Communicate with High Speed GMLAN Device |
| K43 | Power Steering Control Module | High Speed GMLAN | Scan Tool Does Not Communicate with High Speed GMLAN Device |
| K71 / T12 | Transmission Control Module / Automatic Transmission Assembly | High Speed GMLAN | Scan Tool Does Not Communicate with High Speed GMLAN Device |
| K73 | Telematics Communication Interface Control Module |
|
|
| K83 | Park Brake Control Module | High Speed GMLAN | Scan Tool Does Not Communicate with High Speed GMLAN Device |
| K85 | Passenger Presence Module | Low Speed GMLAN | Scan Tool Does Not Communicate with Low Speed GMLAN Device |
| K86 | Advanced Parking Assist Control Module | Low Speed GMLAN | Scan Tool Does Not Communicate with Low Speed GMLAN Device |
| M74D | Window Motor - Driver | Local Interconnect Network (LIN) | DTC U1500-U15FF |
| M74LR | Window Motor - Left Rear | Local Interconnect Network (LIN) | DTC U1500-U15FF |
| M74P | Window Motor - Passenger | Local Interconnect Network (LIN) | DTC U1500-U15FF |
| M74RR | Window Motor - Right Rear | Local Interconnect Network (LIN) | DTC U1500-U15FF |
| M75 | Windshield Wiper Motor | Local Interconnect Network (LIN) | DTC U1500-U15FF |
| P2 | Transmission Shift Lever Position Indicator | Local Interconnect Network (LIN) | DTC U1500-U15FF |
| P16 | Instrument Cluster | Low Speed GMLAN | Scan Tool Does Not Communicate with Low Speed GMLAN Device |
| S79D | Window Switch - Driver | Local Interconnect Network (LIN) | DTC U1500-U15FF |
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.