B1327: Driver Front Sensor Short

SRS fault

What B1327 means

The driver front impact sensor sits near the front of the car on the left side, where it can feel a frontal collision early. Its harness carries a controlled supply and a signal back to the restraint module. When battery voltage appears on one of those conductors from an outside source, the module can no longer trust anything the sensor says, so it stores B1327 and disables the system.

A short to power almost always comes from a physical problem where two harnesses meet or where insulation has failed. The front of the car is full of powered circuits for lighting, cooling fans, and the charging system, and the sensor harness runs right through that area. Water is the other common bridge, since it connects adjacent terminals inside a flooded connector.

Common causes

• Chafed insulation letting the sensor wire contact a powered conductor
• Water and corrosion inside the sensor connector bridging to a powered pin
• Front collision damage that crushed the harness against a power feed
• Aftermarket lighting, winch, or accessory wiring spliced into the front harness
• Damage during headlight, radiator, or bumper cover service
• Rodent damage exposing conductors in the front harness bundle

Crash data or hardware fault?

The definition names an electrical condition on a harness, which reads as a live fault rather than a deployment record. Confirm that on the vehicle, since a car that has also been wrecked can be holding both. Live faults track what the module measures right now. Crash data is the permanent entry written at deployment, and it stays in the module regardless of any repair.

Does our reset clear it?

Repair the short before you clear anything, because voltage on a restraint harness is a real hazard and the module will report it again at the next check. Once the extra supply is removed and the sensor circuit reads correctly, the code clears normally. A vehicle that deployed will also have crash data locked in the module, and that is what our mail-in reset service removes after the repairs.

Which makes throw it

B1327 shows up on Buick, Cadillac, Chevrolet, GMC, and Hyundai. The GM brands share a code table with each other, and Hyundai uses the same number for the same condition, so the diagnostic approach carries across all five.

What to do next

Disconnect the battery and let the system power down before probing, then look for added wiring and for evidence of front end repair work, since aftermarket installs and collision damage cause most short to power faults. Follow the sensor harness through the front of the car with the connector unplugged and check each conductor against battery positive. Repair the insulation properly rather than taping over it. Related codes: B0100, U0151, 93C1, B0053.