Do you still have the old sensor, you may be in luck, you can diagnose by simple ohmic checks with a DVM (Digital Volt Meter).
The "connector" may still be ok, but is the wiring ok?
This sensor uses a "variable resistor" set up like a divider to check "tension" on the seat belt it's with. IF one of the wires has opened up or is damamged and is shorting out - these conditions causes the voltages the SRS "Expects" - to be out of normal range and sets a trouble code.
You just need to see if voltages are getting to the unit in it's connector, and they can return to the SRS sensor under the main console under the E-Brake handle - if that harness is damaged or not plugged in, there's your reason, just reset/fix the connector and then you can also restore the OEM connector and see if it will clear the code.
