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.
2021 GMC Acadia SLFACTORY OEM SERVICE PROCEDURE
Section 249 (Data Communications Description And Operation)
WARNING: This page is about a different car, the 2020 GMC Acadia. However, it is still accessible from the selected car via links, so may be relevant.
- Description and Operation
- Data Link Communications Description and Operation
- Notes
- Data Link Communications Overview
- K9 Body Control Module (BCM)
- K56 Serial Data Gateway Module (Gen 3)
- High Speed GMLAN Bus (Circuits 2500 & 2501)
- High Speed DLC Bus (Circuits 1978 & 1979)
- Chassis High Speed GMLAN Bus (Circuits 6105 & 6106) (if equipped)
- Chassis High Speed DLC Bus (Circuits 1980 & 1981)
- Powertrain High Speed GMLAN Bus (Circuits 7493 & 7494) (if equipped)
- Powertrain Sensor High Speed GMLAN Bus (Circuits 4498 & 4499) (if equipped)
- Object High Speed GMLAN Bus (Circuits 3811 & 3813) (if equipped)
- Object High Speed DLC Bus (Circuits 2089 & 2090)
- Gateway Isolated High Speed GMLAN Bus (Circuits 1304 & 1305)
- Gateway Expansion High Speed GMLAN Bus (Circuits 3935 & 3936)
- Ethernet Bus (if equipped)
- Media Oriented Systems Transport (MOST) Bus (Circuits 3997 & 3998) (if equipped)
- FlexRay Bus (if equipped)
- Low Speed GMLAN Bus (Circuit 5060)
- Low Speed DLC Bus (Circuit 2100)
- Gateway Isolated Low Speed GMLAN Bus (Circuit 1102)
- Local Interconnect Network (LIN) Bus
- Communication Enable Circuit Description
- X84 Data Link Connector (DLC)
- Serial Data Reference
- Data Link Communications Description and Operation
Factory Service Tools
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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.
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