Scan Tool Testing and Procedures

Refer to [1][2]Data Link Communications Schematic, and Data Link Communications Schematic in Data Link Communications.

Diagnostic Chart:

CIRCUIT DESCRIPTION
Modules connected to the Class 2 Serial Data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. Connecting a scan tool to the DLC allows communication with the modules for diagnostic purposes. Diagnostic Trouble Codes (DTCs) may be set due to this symptom and during this diagnostic procedure. Complete the diagnostic procedure in order to ensure all the DTCs are diagnosed and cleared from memory.

DIAGNOSTIC AIDS
^ When the Class 2 Serial Data circuit is shorted to ground, U1300 will be set. Refer to DTC U1300 Class 2 Data Link Low. U1300
^ When the Class 2 Serial Data circuit is shorted to battery positive voltage U1301 will be set. Refer to DTC U1301 Class 2 Data Link High. U1301