Possible Causes

Left curtain air bag module malfunction can be caused by open or short circuit in wiring harness between left curtain air bag module and SAS control module, left curtain air bag module malfunction or SAS control module malfunction.

1. Inspect left curtain air bag module
   
   Using scan tool, inspect resistance for PID/DATA monitor DFCURTRES. See PID/DATA MONITOR & RECORD  under DIAGNOSTICS. If resistance is 1.4-3.2 ohms, replace SAS control module. See SAS CONTROL MODULE  under REMOVAL & INSTALLATION. If resistance is not 1.4-3.2 ohms, go to next step.
2. Inspect left curtain air bag module connector
   
   Turn ignition switch to LOCK position. Disable air bag system. See DISABLING SYSTEM  under DISABLING & ACTIVATING AIR BAG SYSTEM. Disconnect and inspect left curtain air bag module connector. See CURTAIN AIR BAG MODULE  under REMOVAL & INSTALLATION. If left curtain air bag module connector is damaged, replace wiring harness. If left curtain air bag module connector is not damaged, go to next step.
3. Isolate malfunction
   
   Connect leads of 2 ohm resistor across terminals of left curtain air bag module 2-pin connector. Connect negative battery cable. Turn ignition switch to ON position. Using scan tool, inspect PID/DATA monitor OD-D-CURT. Retrieve Diagnostic Trouble Codes (DTCs). See RETRIEVING DIAGNOSTIC TROUBLE CODES (DTCS)  under DIAGNOSTICS. If DTCs B1046, B2773, B2774, B2775 and/or B2776 are retrieved, replace air bag system wiring harness and go to next step. If DTCs B1046, B2773, B2774, B2775 and/or B2776 are not retrieved, replace left curtain air bag module.
4. Inspect SAS control module
   
   Turn ignition switch to LOCK position. Disable air bag system. Connect left curtain air bag module connector. Connect negative battery cable. Retrieve DTCs. If DTCs B1046, B2773, B2774, B2775 and/or B2776 are retrieved, replace SAS control module. If DTCs B1046, B2773, B2774, B2775 and/or B2776 are not retrieved, test is complete.