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Cellular Communication Diagnostic System Check

WARNING: This page is about a different car, the 2002 Oldsmobile Aurora. However, it is still accessible from the selected car via links, so may be relevant.
  1. Connect scan tool to Data Link Connector (DLC). DLC is located below driver side of instrument panel, near steering column. If scan tool powers up, go to next step. If scan tool does not power up, perform TEST A: SCAN TOOL DOES NOT POWER UP  under SYSTEM TESTS.
  2. Turn ignition switch to RUN position. Using scan tool, attempt to communicate with cellular telephone module and OnStar® Vehicle Interface Unit (VIU), or Vehicle Communication Interface Module (VCIM). If scan tool communicates with cellular telephone module and VIU or VCIM, go to next step. If scan tool does not communicate with cellular telephone module and VIU or VCIM, perform TEST B: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE  under SYSTEM TESTS.
    3. CAUTION: Engine may start. Turn ignition switch to OFF position as soon as you have observed crank power mode.
  3. Using scan tool, access CLASS 2 POWER MODE. Cycle ignition switch through all positions while observing ignition switch power mode parameter. If ignition switch parameter matches ignition switch positions, go to next step. If ignition switch parameter does not match ignition switch positions, perform TEST C: POWER MODE MISMATCH  under SYSTEM TESTS.
    4. NOTE: Vehicle will be equipped with one of two OnStar® systems, Generation 2.6 or Generation F1. Access MODULE 2, MODULE I.D. Information screen on scan tool to determine which system is installed.
  4. Using scan tool, select DISPLAY DTCs function for cellular telephone module and VIU or VCIM. If scan tool displays any DTCs, go to next step. If scan tool does not display any DTCs, repair cellular phone as necessary.
  5. If scan tool displays any DTCs which begin with "U", go to next step. If scan tool does not display any DTCs which begin with "U", go to step  7.
  6. If scan tool displays DTC U1500, perform DTC U1500: ONSTAR® SERIAL DATA CIRCUIT FAILURE  under DIAGNOSTIC TESTS. If scan tool does not display DTC U1500, perform TEST B: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE  under SYSTEM TESTS.
  7. If scan tool does not display DTC B1000, B1004, B1007 or B1009, go to next step. If scan tool displays DTCs B1000, B1004, B1007 or B1009, perform appropriate test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .
  8. If scan tool displays DTC B1327, perform appropriate test. See DTC B1327: BATTERY/SOURCE VOLTAGE LOW under DIAGNOSTIC TESTS in GENERATORS & REGULATORS - AURORA article in ELECTRICAL. If scan tool does not display DTCs B1327, perform appropriate test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS .
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