What does it mean?
B1999 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Passenger-side Side Air Bag Module Circuit Resistance Low .
Symptoms
- Airbag warning lamp on all the time with that airbag deactivated
- Code returns immediately after clearing
- Fault sometimes present only at certain seat positions
- Passenger airbag status indicator behaving abnormally
- Vehicle cannot pass inspection with the restraint lamp lit
Likely causes
- Insulation crushed under the seat allowing the two squib wires to touch
- Corrosion and moisture inside the yellow connector lowering the loop resistance
- Shorting bar still engaged or broken so it links both terminals
- Wiring pinched by the seat frame, the recline mechanism or an aftermarket seat cover
- Internal fault inside the passenger side airbag module
- Non approved repair, splice or replacement connector in the squib circuit
- Measuring circuit fault inside the restraint control module
How to fix it
- Note whether the code is current and whether seat position influences it
- Make the system safe: ignition off, battery disconnected and the specified waiting period observed
- Fit an approved squib load tool in place of the airbag rather than measuring the inflator, then recheck the code
- If the code clears with the load tool fitted the airbag module is faulty, if it remains the wiring or control module is
- Inspect the connector for corrosion, moisture, bent pins and a damaged shorting bar
- Check the harness under the seat and along the recline mechanism for crushing while moving the seat
- Repair the harness or replace the airbag module, then clear the code and confirm the lamp performs its self check and goes out