Possible Causes

A driver-side seat belt pretensioner circuit shorted to battery could be caused by a short to battery on Green/Blue wire (circuit 15S-JA33), a short to battery on Black/Blue wire (circuit 91S-JA33), a short to battery in driver-side seat belt pretensioner or an internal RCM fault.

1. Check driver-side pretensioner
   
   Turn ignition off. Disable air bag system. See DISABLING SYSTEM  under DISABLING & ACTIVATING AIR BAG SYSTEM. Turn ignition switch to RUN position. Perform on-demand self-test. See ON-DEMAND SELF-TEST  under DIAGNOSTICS. If DTC B1878 is retrieved, go to next step. If DTC B1878 is not retrieved, replace driver-side seat belt pretensioner. See SEAT BELT PRETENSIONER  under REMOVAL & INSTALLATION. Activate air bag system. See ACTIVATING SYSTEM  under DISABLING & ACTIVATING AIR BAG SYSTEM. Clear DTCs. Repeat on-demand self-test.
2. Check driver-side seat belt pretensioner circuits
   
   Turn ignition off. Access RCM and disconnect harness connector C423. See RESTRAINTS CONTROL MODULE  under REMOVAL & INSTALLATION. Disconnect driver-side seat belt pretensioner simulator. Turn ignition switch to RUN position. Measure voltage between ground and RCM harness connector C423, terminal No. 11 (Green/Blue wire). See Figure. Measure voltage between ground and RCM harness connector C423, terminal No. 12 (Black/Blue wire). If any voltage is present, repair Green/Blue or Black/Blue wire as necessary. Activate air bag system. See ACTIVATING SYSTEM  under DISABLING & ACTIVATING AIR BAG SYSTEM. Clear DTCs. Repeat on-demand self-test. If no voltage is present, replace RCM. Activate air bag system. See ACTIVATING SYSTEM  under DISABLING & ACTIVATING AIR BAG SYSTEM. Clear DTCs. Repeat on-demand self-test.