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Test G: Scan Tool Does Not Communicate With Class 2 Device

  1. Install scan tool. If scan tool powers up, go to next step. If scan tool does not power up, diagnose data link connector circuit. See DATA LINK CONNECTOR article in WIRING DIAGRAMS.
  2. Turn ignition on, with engine off. Using scan tool, attempt to communicate with each module on the class 2 serial data circuit. If scan tool communicates with any module on the class 2 serial data circuit, go to next step. If scan tool does not communicate with any module on the class 2 serial data circuit, go to step  5.
  3. Using scan tool, select display DTCs function for each module. Record all displayed DTCs, DTC status and module which set the DTC. If recorded DTCs are in the range of U1000 to U1255, go to next step. If recorded DTCs are not in the range of U1000 to U1255, problem is intermittent.
  4. If DTC U1000 or U1255 is the only DTC displayed, diagnose affected DTC(s). If other DTC(s) are displayed, diagnose affected DTC(s).
  5. Turn ignition off. Disconnect scan tool from DLC. Check for poor connections at DLC terminals No. 2 and 5. Repair as necessary. If connections are okay, go to next step.
  6. Check for open in DLC ground circuit terminal No. 5. Repair as necessary. If circuit is okay, go to next step.
  7. Disconnect splice pack SP205, located behind headlight switch. Check for poor connections at splice pack. Repair as necessary. After repairs, go to next step.
  8. Check class 2 serial data circuit for open or short between DLC and splice pack SP205. Repair as necessary. After repairs, go to next step.
  9. Using correct terminal adapter from Connector Adapter Test Kit (J35616-A), connect a jumper wire to terminal "A" of splice pack SP205. Connect other end of jumper wire (with correct terminal adapter) to terminal "M" of splice pack SP205. Turn ignition on, with engine off. Using scan tool, attempt to communicate with BCM. If scan tool communicates with BCM, go to step  11. If scan tool does not communicate with BCM, go to next step.
  10. Turn ignition off. Disconnect BCM harness connector. Check class 2 serial data circuit between splice pack SP205 and BCM for short to ground or short to voltage. Turn ignition on, with engine off when testing for short to voltage. Repair as necessary. After repairs, go to step  28. If circuit is okay, go to step  26.
  11. Connect another jumper wire from Connector Adapter Test Kit (J35616-A) to jumper wire connected to terminal "A" of splice pack SP205. Connect other end of jumper wire (with correct terminal adapter) to terminal "B" of splice pack SP205. Turn ignition on, with engine off. Using scan tool, attempt to communicate with PCM/VCM. If scan tool communicates with PCM/VCM, go to step  13. If scan tool does not communicate with PCM/VCM, go to next step.
  12. Turn ignition off. Disconnect PCM/VCM harness connector. Check class 2 serial data circuit between splice pack SP205 and PCM/VCM for short to ground or short to voltage. Turn ignition on, with engine off when testing for short to voltage. Repair as necessary. After repairs, go step  28. If circuit is okay, go to step  26.
  13. Disconnect jumper wire from splice pack SP205 terminal "B". Connect jumper wire to terminal "C" of splice pack SP205. Turn ignition on, with engine off. Using scan tool, attempt to communicate with Automatic Transfer Case (ATC) control module. If scan tool communicates with ATC control module, go to step  15. If scan tool does not communicate with ATC control module, go to next step.
  14. Turn ignition off. Disconnect ATC control module harness connector. Check class 2 serial data circuit between splice pack SP205 and ATC for short to ground or short to voltage. Turn ignition on, with engine off when testing for short to voltage. Repair as necessary. After repairs, go to step  28. If circuit is okay, go to step  26.
  15. Disconnect jumper wire from terminal "C" of splice pack SP205. Connect jumper wire to terminal "E" of splice pack SP205. Turn ignition on, with engine off. Using scan tool, attempt to communicate with EBCM. If scan tool communicates with EBCM, go to step  17. If scan tool does not communicate with EBCM, go to next step.
  16. Turn ignition off. Disconnect EBCM harness connector. Check the class 2 serial data circuit between splice pack SP205 and EBCM for short to ground or short to voltage. Turn ignition on, with engine off when testing for short to voltage. Repair as necessary. After repairs, go to step  28. If circuit is okay, go to step  26.
  17. Disconnect jumper wire from terminal "E" of splice pack SP205. Connect jumper wire to terminal "F" of splice pack SP205. Turn ignition on, with engine off. Using scan tool, attempt to communicate with Sensing and Diagnostic Module (SDM). If scan tool communicates with SDM, go to step  19. If scan tool does not communicate with SDM, go to next step.
  18. Turn ignition off. Disconnect SDM harness connector. Check class 2 serial data circuit between splice pack SP205 and SDM for short to ground or short to voltage. Turn ignition on, with engine off when testing for short to voltage. Repair as necessary. After repairs, go to step  28. If circuit is okay, go to step  26.
  19. Disconnect jumper wire from terminal "F" of splice pack SP205. Connect jumper wire to terminal "G" of splice pack SP205. Turn ignition on, with engine off. Using scan tool, attempt to communicate with Instrument Panel Cluster (IPC). If scan tool communicates with IPC, go to step  21. If scan tool does not communicate with IPC, go to next step.
  20. Turn ignition off. Disconnect IPC harness connector. Check class 2 serial data circuit between splice pack SP205 and IPC for short to ground or short to voltage. Turn ignition on, with engine off when testing for short to voltage. Repair as necessary. After repairs, go to step  28. If circuit is okay, go to step  26.
  21. Disconnect jumper wire from terminal "G" of splice pack SP205. Connect jumper wire to terminal "H" of splice pack SP205. Using scan tool, attempt to communicate with Suspension Control Module (SCM). If scan tool communicates with SCM, go to step  23. If scan tool does not communicate with SCM, go to next step.
  22. Turn off ignition. Disconnect SCM harness connector. Check class 2 serial data circuit between splice pack SP205 and SCM for short to ground or short to voltage. Turn ignition on, with engine off when testing for short to voltage. Repair as necessary. After repairs, go to step  28. After repairs, go to next step.
  23. Disconnect jumper wire from terminal "H" of splice pack SP205. Connect jumper wire to terminal "L" of splice pack SP205. Using scan tool, attempt to communicate with HVAC control module. If scan tool communicates with HVAC control module, go to step  25. If scan tool does not communicate with HVAC control module, go to next step.
  24. Turn ignition off. Disconnect HVAC control module harness connector. Check class 2 serial data circuit between splice pack SP205 and HVAC control module for short to voltage. Turn ignition on, with engine off when testing for short to voltage. Repair as necessary. After repairs, go to step  28. If circuit is okay, go to next step.
  25. Turn ignition off. Check class 2 serial data circuit for cellular phone ready wiring between splice pack SP205 and body wiring harness junction block for short to ground or short to voltage. Turn ignition on, with engine off when testing for short to voltage. Repair as necessary. After repairs, go to step  28. If circuit is okay, problem is intermittent.
  26. Inspect for poor connections at class 2 serial data circuit of module that is not communicating. Repair as necessary. After repairs, go to step  28. If circuit is okay, go to next step.
  27. Replace module which is not communicating. After replacing affected module, go to next step.
  28. Reconnect all disconnected modules and connectors. Turn ignition on, with engine off. Wait for 10 seconds. Scan tool may require a power up reset before communication will occur due to a short on class 2 serial data circuit. Turn off or disconnect scan tool prior to performing this test. Reconnect scan tool. Using scan tool, select display DTCs function for each module. Record all displayed DTCs and DTC status. Diagnose affected DTC(s). After diagnosing DTC(s), clear DTCs.
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