S15/T15 Sonoma P/U 2WD L4-2.2L VIN 5 Flex Fuel (2001)
Information Bus: Symptom Related Diagnostic Procedures
Scan Tool Does Not Communicate With Class 2 Device
CIRCUIT DESCRIPTION
Modules connected to the class 2 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.
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
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The BCM detects that the ignition is ON and sends the appropriate power mode message to the other modules. Therefore, the BCM must be
connected to the DLC for any other module to communicate with the scan tool.
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When the class 2 circuit is shorted to battery negative voltage, U1300 will be set. Refer to DTC U1300. See: Testing and Inspection/Diagnostic
Trouble Code Tests and Associated Procedures/U Code Charts/U1300
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When the class 2 circuit is shorted to battery positive voltage U1301 will be set. Refer to DTC U1301. See: Testing and Inspection/Diagnostic
Trouble Code Tests and Associated Procedures/U Code Charts/U1301
TEST DESCRIPTION
