Scan Tool Testing and Procedures

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 (DLC) 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 (Diesel Engine)DTC U0100-U0299 (HP2) Testing and Inspection Testing and Inspection
- DTC U1800, U2105 or U2106-Refer to DTC U1800, U2105, U2106, or U2108 U1800 U2105 U2106 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.