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Test Procedure

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 .
  2. Turn ignition switch to RUN position. Using scan tool, attempt to communicate with each module on Class 2 serial data circuit. See CLASS 2 SERIAL DATA LINE  under DESCRIPTION & OPERATION. If scan tool communicates with any module, go to next step. If scan tool does not communicate with any module, go to step  8.
  3. Using scan tool, select DISPLAY DTCs function for each module. Record all DTCs, status and module which stored DTC. If any DTCs within U1000 or U1305 are retrieved, go to next step. If any DTCs within U1000 to U1305 are not retrieved, go to step  7.
  4. If DTCs U1300, U1301 or U1305 are retrieved from any module, go to next step. If DTCs U1300, U1301 or U1305 are not retrieved from any module, go to step  6.
    5. NOTE: Turn ignition switch to RUN position, when testing for a short to voltage. Use DVOM MIN/MAX function to capture intermittent conditions.
  5. Inspect Class 2 serial data circuit (Purple wire) between each module on circuit for an intermittent short to ground or short to voltage. See CONNECTOR IDENTIFICATION . See WIRING DIAGRAMS . See INTERMITTENTS . If problem does not exist, go to next step. If problem exists, repair Purple wire as necessary. After repair, go to step  17.
  6. If ONLY either or both DTCs U1000 and U1255 is/are displayed, perform DTC U1000 & U1255: CLASS 2 COMMUNICATION MALFUNCTION  under DIAGNOSTIC TESTS. If DTC U1001-U1255 is displayed, perform DTC U1001-U1254: LOSS OF XXX COMMUNICATION  under DIAGNOSTIC TESTS.
  7. Diagnose non-communicating module by performing DTC U1001-U1254: LOSS OF XXX COMMUNICATION  under DIAGNOSTIC TESTS. After repair procedure has been complete, perform appropriate diagnostic system check for suspect system. See BODY CONTROL SYSTEM DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM.
  8. Turn ignition switch to OFF position. Disconnect scan tool from DLC. Inspect DLC for poor connections and terminal tension. If problem does not exist, go to next step. If problem exists, repair DLC as necessary. After repair, perform appropriate diagnostic system check for suspect system. See BODY CONTROL SYSTEM DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM.
  9. Inspect ground circuits for an open or high resistance between ground and DLC terminal Nos. 4 (Black wire) and 5 (Black/White wire), individually. See Figure. See WIRING DIAGRAMS . If problem does not exist, go to next step. If problem exists, repair Black wire and/or Black/White wire as necessary. After repair, perform appropriate diagnostic system check for suspect system. See BODY CONTROL SYSTEM DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM.
  10. Inspect Purple wire for an open, high resistance or short to ground/voltage between DLC terminal No. 2 and inline harness connector C201 terminal A5. See Figure. Inspect Purple wire for an open, high resistance or short to ground/voltage between Dash Integration Module (DIM) connector C2 terminal A12 and Theft Deterrent Control (TDC) module connector C1 terminal C8, individually. See Figure and Figure . If problem does not exist, go to next step. If problem exists, repair Purple wire as necessary. After repair, perform appropriate diagnostic system check for suspect system. See DIAGNOSTIC SYSTEM CHECK  table under SELF-DIAGNOSTIC SYSTEM.See BODY CONTROL SYSTEM DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM.
  11. Turn ignition switch to OFF position. Disconnect TDC module connector and IPM connector C2. Turn ignition switch to RUN position. Using scan tool, attempt to communicate with modules still connected to DLC. If scan tool does not communicate with any remaining modules, go to next step. If scan tool communicates with any remaining module, go to step  14.
    12. NOTE: For Class 2 serial data line module sequence, see WIRING DIAGRAMS .
  12. Turn ignition switch to OFF position. Disconnect radio. Turn ignition switch to RUN position. Using scan tool, attempt to communicate with modules still connected to DLC. If communication with modules is restored when radio is disconnected, go to step  14. If communication is not restored when radio is disconnected, turn ignition switch to OFF position. Disconnect next module towards DLC. Turn ignition switch to RUN position and attempt to communicate with modules still connected to DLC. Repeat procedure until communication with remaining modules is restored. Disconnect modules in following order:
    • Theft Deterrent Control (TDC) Module
    • Instrument Panel Module (IPM)
    • Radio
    • Driver Information Center (DIC)
    • Instrument Panel Cluster (IPC)
    • Driver Door Module (DDM)
    • Powertrain Control Module (PCM)
    • Electronic Brake Control Module (EBCM)
    • Memory Seat Module (MSM) if equipped
    • Remote Control Door Lock Receiver (RCDLR) if equipped
    • Rear Integration Module (RIM)
    • Vehicle Communication Interface Unit (VCIU) or Vehicle Interface Unit (VIU) if equipped
    • CD Changer if equipped
    • Sensing & Diagnostic Module (SDM)
    If scan tool does not communicate with DIM with no other modules connected, go to next step. If communication with modules still connected to DLC is restored when a module is disconnected, go to step  14.
  13. Inspect Purple wire between DIM connector C2 terminal A11 and SDM connector terminal A4. See Figure and Figure . If problem exists, repair as necessary and go to step  17. If problem does not exist, inspect DIM harness connector C2 for poor connections and terminal tension. If no problem is found with connector, replace DIM. See DASH INTEGRATION MODULE  under REMOVAL & INSTALLATION.
  14. Inspect Purple wire for a short to ground/voltage between two previously disconnected modules. See CONNECTOR IDENTIFICATION . See WIRING DIAGRAMS . Turn ignition switch to RUN position to test for short to voltage. If problem does not exist, go to next step. If problem exists, repair Purple wire as necessary. After repair, go to step  17.
  15. Inspect harness connector of last module disconnected for poor connections and terminal tension. If problem does not exist, go to next step. If problem exists, repair harness connector as necessary. After repair, go to step  17.
  16. Replace suspect module which was last disconnected. See REMOVAL & INSTALLATION . Program suspect module, if necessary. See PROGRAMMING . After repair, go to next step.
    17. NOTE: Scan tool may require a power up reset before communication will occur if a short in Class 2 serial data circuit was problem. Turn off or disconnect scan tool before displaying DTCs.
  17. Connect all modules. Connect scan tool to DLC. Turn ignition switch to RUN position, and wait 10 seconds. Using scan tool, select DISPLAY DTCs function for each module. Record all displayed DTCs, and status. If scan tool does not display any current DTCs which begin with "U", go to next step. If scan tool displays any current DTCs which begin with "U", go to step  19.
  18. If scan tool displays any DTCs which do not begin with "U", go to next step. If scan tool does not display any DTCs which do not begin with "U", go to step  20.
  19. Perform appropriate test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . After diagnosis, go to next step.
  20. If all DTCs are not diagnosed, go to step  19. If all DTCs are diagnosed, go to next step.
  21. Using scan tool, clear DTCs. System is okay at this time.
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