Scan Tool Does Not Communicate With Serial Data Line: Testing
- Turn ignition off. Connect scan tool. Disconnect bus bars from Black 12-pin star connectors No. 1 and 2. See COMPONENT LOCATIONS . Connect Serial Data Link Tester (J-42236) to both star connectors. Ensure star connectors correctly correspond with serial data link testing connectors No. 1 and 2. Using serial data link tester, put switch in STAR CONNECTOR #1 position. Rotate rotary switch to "M" position. Turn ignition on. Using scan tool, attempt to establish communication with BCM. If scan tool communicates with BCM, go to next step. If scan tool does not communicate with BCM, go to step 4).
- Ensure switch on serial data link tester is in STAR CONNECTOR #1 position. Using scan tool, attempt to establish communication with the following vehicle systems by rotating rotary switch on serial data link tester as specified:
- "L" - Heating, Ventilation and A/C (HVAC) system.
- "J" - Remote Function Actuator (RFA) system.
- "H" - Real Time Damping (RTD) system (if equipped).
- "G" - Instrument Panel Cluster (IPC).
- "E" - Traction Control System (TCS).
- "D" - Radio system.
- "B" - Powertrain Control Module (PCM).
If scan tool communicates with each system, go to next step. If scan tool does not communicate with each system, go to step 7).
- Turn switch on serial data link tester to STAR CONNECTOR #2 position. Using scan tool, attempt to establish communication with the following vehicle systems by rotating rotary switch on serial data link tester as specified:
- "C" - Left Door Control Module (DCM) system.
- "D" - Right Door Control Module (DCM) system
- "K" - Seat Control Module (SCM) system (if equipped).
If scan tool communicates with each system, go to step 9). If scan tool does not communicate with each system, go to step 7).
- Turn ignition off. Disconnect serial data link tester. Ensure bus bars are still disconnected from star connectors No. 1 and 2. Using DVOM, check continuity of Purple wire between DLC connector terminal No. 2 and star connector No. 1 terminal "A". If continuity exists, go to next step. If continuity does not exist, go to step 10).
- Check continuity between DLC connector terminal No. 2 (Purple wire) and ground. If continuity exists, go to step 10). If continuity does not exist, go to next step.
- Turn ignition on. Using DVOM, check voltage between DLC connector terminal No. 2 (Purple wire) and ground. If any voltage exists, go to step 10). If no voltage exists, go to next step.
- Turn ignition off. Disconnect appropriate system module for system that did not communicate with scan tool. Using DVOM, check for continuity between appropriate terminal on appropriate star connector and ground. If continuity exists, go to step 11). If continuity does not exist, go to next step.
- Turn ignition on. Using test light connected to ground, probe appropriate terminal on appropriate star connector for system that is not communicating. If test light illuminates, go to step 12). If test light does not illuminate, go to step 13).
- Check for intermittent short to ground, short to voltage or open in serial data line circuits. If no problem is found, system is operating properly. If problem is found, repair as necessary. Go to step 14).
- Repair short to ground, short to voltage or open in Purple wire between DLC and star connector No. 1. Go to step 14).
- Repair short to ground in appropriate wire between unresponsive module and appropriate star connector. Go to step 14).
- Repair short to voltage in appropriate wire between unresponsive module and appropriate star connector. Go to step 14).
- Replace appropriate module. Go to next step.
- Turn ignition off. Reinstall all components or connectors. Clear DTCs. Ensure system is operating properly.