What does it mean?
B1886 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Passenger-Side Pre-Tensioner Seat Belt Circuit Resistance Low .
Symptoms
- Air bag warning lamp permanently lit
- Passenger belt pretensioner disabled and will not tension the belt in an impact
- Code often appears after passenger seat removal, a wet footwell or an accessory fitment
- Fault stays present through ignition cycles when the short is solid
- Warning message about the restraint system on vehicles with an information display
Likely causes
- Firing wires chafed against each other where the harness passes a sharp bracket under the passenger seat
- Corrosion and water inside the under seat connector linking the two pins
- Connector shorting bar stuck in the closed position after being damaged
- Internal short in the passenger pretensioner igniter
- Harness pinched by the seat foot or rail so both conductors are crushed together
- Poorly made previous repair with untwisted strands touching
- Restraint control module measuring circuit failure
How to fix it
- Apply the air bag safety procedure before touching any restraint connector
- Read codes and freeze frame, and establish whether the low resistance is constant or comes and goes with seat movement
- Disconnect the pretensioner and measure between the two harness conductors with the module also unplugged to locate the short
- Open and inspect the under seat connector for water, corrosion and a shorting bar that fails to open when mated
- Trace the harness along the seat rails and check every point where it can be crushed or rub a metal edge
- Rework any previous splice using the correct terminals and full insulation
- Replace the restraint control module only after wiring and pretensioner have both tested good