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.
Class 2 Serial Data Link
Scan tool will power up with ignition switch in OFF position. Some modules will not communicate unless ignition switch is in RUN position and Power Mode Master (PMM) module (DIM) sends appropriate power mode message. Data link is configured as a ring with discrete lines entering and leaving each module. This allows communication with modules on ring if one of two discrete circuits is open. Modules on data link include:
- Driver Door Module (DDM)
- Dash Integration Module (DIM)
- Driver Information Center (DIC)
- Electronic Brake Control Module (EBCM)
- Instrument Panel Cluster (IPC)
- Instrument Panel Module (IPM)
- Memory Seat Module (MSM)
- Powertrain Control Module (PCM)
- Radio
- Rear Integration Module (RIM)
- Remote Control Door Lock Receiver (RCDLR)
- Sensing & Diagnostic Module (SDM)
- CD Changer
- Theft Deterrent Control (TDC) Module
- Vehicle Communication Interface Unit (VCIM)
- Vehicle Interface Unit (VIU)
Power door serial data circuit does not communicate with scan tool via DLC. Power door serial data information is interpreted by Driver Door Module (DDM) and transmitted on Class 2 data link by DDM. Door system serial data circuit is used for serial data communication between each door module and driver door switch assembly (DDSA).
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.