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Scan Tool Does Not Communicate With Class 2 Serial Data Line

NOTE: To identify components on class 2 serial data line, see appropriate wiring diagram in SYSTEM WIRING DIAGRAMS.
  1. Connect scan tool to another vehicle to ensure proper operation of scan tool. If scan tool cannot communicate with another vehicle, refer to scan tool manufacturer's instructions. If scan tool can communicate with another vehicle, go to next step.
  2. Turn ignition off. Ensure connections of Data Link Connector (DLC) are clean and tight. DLC is located under instrument panel, left of steering column. Check for any terminals that are not seated properly. Repair as necessary. If connections are okay, go to next step.
  3. Turn ignition on, with engine off. Using DVOM, check voltage between DLC connector terminals No. 16 (Orange wire) and No. 4 (Black wire). Check voltage between DLC terminals No. 16 (Orange wire) and No. 5 (Black/White wire). If battery voltage exists at both terminals, go to step 7). If battery voltage does not exist at both terminals, go to next step.
  4. Check voltage between DLC connector terminal No. 16 (Orange wire) and chassis ground. If battery voltage exists, go to next step. If battery voltage does not exist, repair open or short to ground in Orange wire between DLC connector and I/P BEC Gray, 68-pin connector C1.
  5. Check voltage between DLC connector terminals No. 16 (Orange wire) and No. 5 (Black/White wire). If battery voltage exists, go to next step. If battery voltage does not exist, repair open in Black/White wire between DLC connector and ground.
  6. Check voltage between DLC connector terminals No. 16 (Orange wire) and No. 4 (Black wire). If battery voltage exists, go to next step, if battery voltage does not exist, repair open in Black wire between DLC connector and ground.
  7. Turn ignition off. Disconnect all modules of class 2 serial data line. Turn ignition on. Using DVOM, check voltage between DLC connector terminal No. 2 (Purple wire) and ground. If battery voltage exists, repair short to voltage in Purple wire to DLC connector. If battery voltage does not exist, go to next step.
  8. Using DVOM, check resistance between DLC connector terminal No. 2 (Purple wire) and ground. If resistance is 5 ohms or less, go to next step. If resistance is not 5 ohms or less, repair short to ground in Purple wire to DLC connector.
  9. Restore connections to class 2 serial data modules one at a time in the following order. Establish communications with each module after restoring connection. If communications cannot be established with module last connected, replace that module.
    • Driver Door Module (DDM)
    • Cellular Telephone Module (If Equipped)
    • Remote Function Actuator (RFA) Module
    • Sensing And Diagnostic Module (SDM)
    • PASS-Key III Module
    • Instrument Pane Cluster (IPC)
    • HVAC Programmer
    • Body Control Module (BCM)
    • Powertrain Control Module (PCM)
    • Electronic Brake And Traction Control Module (EBTCM)
    • Memory Seat Module (If Equipped)
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