What does B0066 mean on a Chevy?

B0066. Left front driver pretensioner deployment loop short to ground or voltage out of range. The module may disable the pretensioner. Applies to Chevrolet, GMC, Buick, Cadillac, Pontiac, Oldsmobile and Saturn models that use this code.

What causes B0066 on a Chevy?

Left front driver pretensioner harness shorted to ground Left front driver pretensioner wiring chafed under the seat track or sill plate Corroded or loose left front driver pretensioner connector Left front driver pretensioner with an internal ground short Faulty driver inside the sensing and diagnostic module for that loop

How do I fix B0066 on a Chevy?

Confirm the code with a Tech2 or GDS2 and read the left front driver pretensioner loop status Disconnect the battery and wait at least three minutes before touching any SRS circuit Inspect the left front driver pretensioner wiring under the seat track and sill plate for chafe Test the left front driver pretensioner circuit for shorts to ground and shorts to battery Replace the left front driver pretensioner only if the wiring tests good, using a qualified SRS technician Clear the code and retest

Code

B0066

Left front driver pretensioner deployment loop short to ground or voltage out of range

Category: Body
Severity: Airbag Light
Applies to: Chevrolet, GMC, Buick, Cadillac, Pontiac, Oldsmobile and Saturn models that use this code
Related: No single generic twin. See OBD Codes List

What it means

B0066. Left front driver pretensioner deployment loop short to ground or voltage out of range. The module may disable the pretensioner. This Chevy-enhanced code applies to Chevrolet, GMC, Buick, Cadillac, Pontiac, Oldsmobile and Saturn models that use this code.

Findings, check these first

Left front driver pretensioner harness shorted to ground
Left front driver pretensioner wiring chafed under the seat track or sill plate
Corroded or loose left front driver pretensioner connector
Left front driver pretensioner with an internal ground short
Faulty driver inside the sensing and diagnostic module for that loop

Standard procedure

Confirm the code with a Tech2 or GDS2 and read the left front driver pretensioner loop status
Disconnect the battery and wait at least three minutes before touching any SRS circuit
Inspect the left front driver pretensioner wiring under the seat track and sill plate for chafe
Test the left front driver pretensioner circuit for shorts to ground and shorts to battery
Replace the left front driver pretensioner only if the wiring tests good, using a qualified SRS technician
Clear the code and retest

Look up another code

Press / to jump to the box. Chevy-enhanced powertrain, body, chassis and network codes.

Sources and review

Review: checked against the recorded source material.

Code B0066 definition | OBDII.pro
live manufacturer definition (obdii.pro)
Supports: GM manufacturer meaning for B0066
Fetched directly. The GM entry is the brand-family meaning used here. This site is independent of engine-codes and autocodes.
B0066 CHEVROLET Left Front/Driver Pretensioner Deployment Loop Voltage Out of Range | Engine-Codes.com
archived reference page (engine-codes.com via Wayback Machine)
Supports: Chevrolet meaning and possible causes
Fetched directly. Model and year fitment remain curator claims.
B0066 CHEVROLET Left Front/Driver Pretensioner Deployment Loop Voltage Out of Range | AutoCodes.com
archived reference page (autocodes.com via Wayback Machine)
Supports: corroboration of Chevrolet meaning and causes
Same Chevrolet text as the engine-codes page (both sites share one publisher).

Last updated 2026-10-10.

Report a correction for B0066. Include your vehicle, the issue and a source if you have one.