DTC U1000: Class-2 Communication Data Link Malfunction
- Perform VEHICLE ON-BOARD DIAGNOSTIC SYSTEM CHECK under SELF-DIAGNOSTIC SYSTEM. If body control module diagnostic system check has been performed, go to next step.
- Observe scan tool display for DTC U1000. If scan tool displays LAST TEST FAILED for DTC U1000, go to next step. If scan tool does not display LAST TEST FAILED for DTC U1000, problem is intermittent. Check for open or poor connection in serial data line (Purple wire). See DATA LINK CONNECTORS article in WIRING DIAGRAMS. Repair as necessary and retest operation.
- Attempt to establish communication with Sensing and Diagnostic Module (SDM). If scan tool communicates with SDM, go to next step. If scan tool does not communicate with SDM, go to DTC U1088: LOST COMMUNICATIONS WITH SENSING AND DIAGNOSTIC MODULE (SDM) .
- Using scan tool, perform instrument panel cluster lamp and gauge special test. If instrument panel responds to scan tool commands, go to next step. If instrument panel does not respond to scan tool commands, go to DTC U1096: LOST COMMUNICATIONS WITH INSTRUMENT PANEL CLUSTER .
- Using scan tool, attempt to establish communications with Electronic Brake/Traction Control Module (EBTCM). If scan tool communicates with EBTCM, go to next step. If scan tool does not communicate with EBTCM, go to DTC U1040: LOST COMMUNICATIONS WITH ELECTRONIC BRAKE/TRACTION CONTROL MODULE (EBTCM) .
- Using scan tool, attempt to establish communications with Powertrain Control Module (PCM). If scan tool communicates with PCM, go to next step. If scan tool does not communicate with PCM, go to DTC U1016: LOST COMMUNICATIONS WITH ENGINE CONTROLS SYSTEM .
- Problem is intermittent. Check for open or poor connection in serial data line (Purple wire). See DATA LINK CONNECTORS article in WIRING DIAGRAMS. Repair as necessary and retest operation.