Possible Causes

Left side air bag circuit short to ground could be caused by short to ground in Red/Green wire (circuit No. 30S-JA37), short to ground in Black/Green wire (circuit No. 31S-JA37), short to ground in left side air bag module, or RCM internal fault.

1. Check for hard or intermittent DTCs
   
   Turn ignition switch to OFF position. Connect scan tool to Data Link Connector (DLC). See USING SCAN TOOL  under DIAGNOSTICS. Turn ignition switch to RUN position. Retrieve and record any continuous DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES (DTCS)  under DIAGNOSTICS. Clear continuous DTCs. See CLEARING FAULT CODES  under DIAGNOSTICS. Perform on-demand self-test. See ON-DEMAND SELF-TEST  under DIAGNOSTICS. If DTC B1993 was retrieved during on-demand self-test, fault is hard. Go to next step. If DTC B1993 was not retrieved, fault is intermittent. Go to step  5 .
2. Check left side air bag module
   
   Turn ignition switch to OFF position. Disable air bag system. See DISABLING SYSTEM  under DISABLING & ACTIVATING AIR BAG SYSTEM. Turn ignition switch to RUN position. Perform on-demand self-test. If DTC B1993 is retrieved, go to next step. If DTC B1993 is not retrieved, replace left side air bag module. See SIDE AIR BAG MODULE  under REMOVAL & INSTALLATION. Go to step  6 .
3. Check left side air bag module circuits
   
   Turn ignition switch to OFF position. Access RCM and disconnect both harness connectors. See RESTRAINTS CONTROL MODULE (RCM)  under REMOVAL & INSTALLATION. Measure resistance between RCM harness connectors C310B, terminal No. 2 (Red/Green wire) and C310A, terminal No. 21 (Black/Red wire). See Figure . If resistance is more than 10 k/ohms, go to next step. If resistance is less than 10 k/ohms, repair short to ground in Red/Green wire. See WIRING DIAGRAMS  . Go to step  6 .
4. Check wiring
   
   Disconnect air bag simulator from left side air bag connector. Inspect all crimps, terminals, wires and connectors in circuit No. 30S-JA37 (Red/Green wire) between air bag module connector and RCM connector C310B, terminal No. 2, and circuit No. 31S-JA37 (Black/Green wire) between air bag module connector and RCM connector C310B, terminal No. 3. Check for pinched wires and damaged connector pin terminals. If any damage is found, repair as necessary. Go to step  6 . If no damage is found, replace RCM. Go to step  6 .
5. Check for intermittent fault
   
   Turn ignition switch to OFF position. Disable air bag system. See DISABLING SYSTEM  under DISABLING & ACTIVATING AIR BAG SYSTEM. Perform on-demand self-test. If DTC B1993 was retrieved during on-demand self-test, check for causes of intermittent fault at or near left side air bag module connector. Repair any intermittent faults found and go to next step. If no intermittent faults are found, go to step  3 . If DTC B1993 was not retrieved during on-demand self-test, check for causes of intermittent short to ground on Red/Green or Black/Green wires. See WIRING DIAGRAMS  . Attempt to recreate fault by flexing wire harness and cycling ignition switch frequently. Repair any intermittent problems found. Go to next step.
6. Check for additional DTCs
   
   Refer to continuous DTCs recorded in step  1 . If any continuous DTCs were retrieved, go to diagnostic trouble code identification table for direction to appropriate test. See DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION  table. DO NOT clear any DTCs until all DTCs have been resolved. If no DTCs were retrieved, reconnect air bag system. Activate air bag system. See ACTIVATING SYSTEM  under DISABLING & ACTIVATING AIR BAG SYSTEM. Clear all DTCs. See CLEARING FAULT CODES  under DIAGNOSTICS.