What it means
B0057 indicates an electrical fault in the right-front (passenger) seat-belt pretensioner circuit. OEM procedures describe it as resistance out of range and/or open/short on the pretensioner high/low control circuits; diagnostic tables spell out conditions such as open/high resistance, short-to-ground, short-to-voltage, or a failed shorting bar in the connector. Charm+1
Symptoms
- SRS indicator on; pretensioner loop inhibited until corrected. Charm
Severity / priority
High (safety-critical). A pretensioner circuit fault can disable that restraint device in a collision. Charm
Common causes
- Open/high resistance from broken or chafed wiring, poor terminal tension, corrosion.
- Short-to-ground or short-to-battery on the pretensioner high/low circuits.
- Connector shorting-bar malfunction at the pretensioner connector. Charm
Diagnostic notes
- Use an SRS-capable scan tool; follow battery disconnect / wait-time procedures and never probe a live inflator/pretensioner.
- Inspect routing under the passenger seat/IP area; several OEM bulletins note harness faults causing B0057/B0058/B0059/B0064/B0065/B0066 and direct harness replacement by side as applicable. NHTSA
- Perform pinpoint tests for open/high resistance and short-to-GND/B+ per service manual. Charm
Possible fixes
- Repair or replace damaged wiring/terminals; correct pin fit and corrosion.
- Replace the pretensioner only if it fails OEM electrical checks.
- Where applicable per TSB, replace the affected door/seat harness identified by the DTC. Clear codes and verify. NHTSA
Primary sources: GM/chevy service-manual extracts for B0057 (conditions and causes), and NHTSA-published OEM TSB instructing harness replacement when B0057/B0058/B0059/B0064/B0065/B0066 are set. Charm+2Charm+2