Montana AWD V6-3.4L VIN E (2004)
Information Bus: Testing and Inspection
Scan Tool Does Not Communicate With Class 2 Device
SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE
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 data link connector (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
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If a short to B+ is present, a history U1301 or U1305 will set in the modules. Refer to DTC U1300, U1301, or U1305.
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If a short to ground is present, a history U1300 or U1305 will set in the modules. Refer to DTC U1300, U1301, or U1305.
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Disconnecting modules and turning the ignition switch to RUN may cause DTCs in these modules. Check for DTCs in each module upon
completion of the required repair.
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The scan tool cannot directly communicate to the rear video/audio/HVAC or video disc player. Diagnosis is accomplished by checking
communications with the radio.
TEST DESCRIPTION