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For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2004 🢒 GMC C Sierra - 2WD 🢒 Engine 🢒 Engine Electrical 🢒 Data Link References

Important: There are modules in this vehicle that communicate on a controller area network (CAN) serial data link. This CAN serial data link is not connected to the data link connector (DLC), and the scan tool cannot communicate on this link. Communication DTCs for this CAN Serial data link may be set by the module acting as an interface to the other serial data links. Refer to Data Link Connector Schematics for CAN serial data circuits. The following DTCs may be set when the interface module detects a loss of communication with a module on the CAN serial data link. Diagnose these DTCs as directed in the DTC Table:

CAN Serial Data - Powertrain Control Module (PCM) and Transmission Control Module (TCM)

   • DTC U0100, U0101, U0105 or U0106--Refer to DTC U0100-U0299
   • DTC U1800, U2105 or U2106--Refer to DTC U1800, U2105, U2106, or U2108
For any other U codes or communication problems, refer to the table below for the correct procedure.

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. This table is used to assist in correcting a communication malfunction between the control module and the scan tool. For the description and operation of these serial data communication circuits refer to Data Link Communications Description and Operation .

Control Module

Data Link Type

Diagnostic Procedure

Schematic Reference: Data Link Connector Schematics

Audio Amplifier

Class 2

Refer to Scan Tool Does Not Communicate with Class 2 Device

Body Control Module (BCM)

Class 2

Refer to Scan Tool Does Not Communicate with Class 2 Device

CD Player (CDX)

Class 2

Refer to Scan Tool Does Not Communicate with Class 2 Device

Digital Radio Receiver (DRR)

Class 2

Refer to Scan Tool Does Not Communicate with Class 2 Device

Driver Door Module (DDM)

Class 2

Refer to Scan Tool Does Not Communicate with Class 2 Device

Driver Seat Module

Class 2

Refer to Scan Tool Does Not Communicate with Class 2 Device

Electronic Brake Control Module (EBCM)

Class 2

Refer to Scan Tool Does Not Communicate with Class 2 Device

Energy Storage Control Module (ESCM)

High Speed GMLAN

Refer to Scan Tool Does Not Communicate with High Speed GMLAN Device

Front Passenger Door Module (PDM)

Class 2

Refer to Scan Tool Does Not Communicate with Class 2 Device

HVAC Control Module

Class 2

Refer to Scan Tool Does Not Communicate with Class 2 Device

Hybrid Control Module (HCM)
    • High Speed GMLAN
    • Class 2

Refer to Scan Tool Does Not Communicate with Class 2 Device

Inflatable Restraint Sensing and Diagnostic Module (SDM)

Class 2

Refer to Scan Tool Does Not Communicate with Class 2 Device

Instrument Panel Cluster (IPC)

Class 2

Refer to Scan Tool Does Not Communicate with Class 2 Device

Electro-Hydraulic Power Steering (EHPS) Module

High Speed GMLAN

Refer to Scan Tool Does Not Communicate with High Speed GMLAN Device

Powertrain Control Module (PCM)
    • High Speed GMLAN
    • Class 2

Refer to Scan Tool Does Not Communicate with Class 2 Device

Radio

Class 2

Refer to Scan Tool Does Not Communicate with Class 2 Device

Rear Seat Audio (RSA) Controller

Class 2

Refer to Scan Tool Does Not Communicate with Class 2 Device

Rear Seat Entertainment (RSE)

Class 2

Refer to Scan Tool Does Not Communicate with Class 2 Device

Rear Wheel Steering Control Module (RWSCM)

Class 2

Refer to Scan Tool Does Not Communicate with Class 2 Device

Starter/Generator Control Module (SGCM)

High Speed GMLAN

Refer to Scan Tool Does Not Communicate with High Speed GMLAN Device

Transfer Case Shift Control Module (TCSCM)

Class 2

Refer to Scan Tool Does Not Communicate with Class 2 Device

Transmission Control Module (TCM)

Class 2

Refer to Scan Tool Does Not Communicate with Class 2 Device

Vehicle Communication Interface Module (VCIM)

Class 2

Refer to Scan Tool Does Not Communicate with Class 2 Device