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Cellular Communication Diagnostic System Check

WARNING: This page is about a different car, the 2001 Cadillac Seville. 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 left side of instrument panel, near steering column. See Figure . 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(R) Vehicle Interface Unit (VIU). If scan tool communicates with cellular telephone module and VIU, go to next step. If scan tool does not communicate with cellular telephone module and VIU, perform TEST B: SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE  under SYSTEM TESTS.
    3. CAUTION: Engine may start during the following step. 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. Using scan tool, select DISPLAY DTCs function for cellular telephone module and VIU. 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(R) 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 in accordance with DTC retrieved. See DIAGNOSTIC TROUBLE CODE DEFINITIONS  .
  8. If scan tool displays DTCs B1327 or B1328, perform appropriate test in accordance with DTC retrieved. See GENERATORS & REGULATORS - SEVILLE article in STARTING & CHARGING SYSTEMS. If scan tool does not display DTCs B1327 or B1328, perform appropriate test in accordance with DTC retrieved. See DIAGNOSTIC TROUBLE CODE DEFINITIONS  .
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