What does it mean?
B1722 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Curtain Airbag (CAB) Circuit Fault .
Symptoms
- Airbag warning lamp on permanently and the curtain airbag is switched off
- Side and curtain protection will not deploy in a rollover or side impact
- The code often appears right after headliner, pillar trim or glass work, or after a water leak
- Additional SRS codes for neighbouring circuits stored at the same time
- Warning lamp may flicker over rough roads if the connection is intermittent
Likely causes
- Pillar or roof-rail connector not relatched after headliner, trim or windscreen work
- Corrosion in the connector caused by water running down the pillar from a leaking seal or sunroof drain
- Wire pinched behind a trim clip or grab handle bolt, giving high resistance or a dead short
- Loom stretched or pulled apart where it crosses the roof rail to the curtain module
- Damaged shorting bar inside the yellow SRS connector holding the circuit shorted
- Curtain airbag inflator with an internally open or shorted squib
- Failed driver channel in the restraint control module
How to fix it
- Read and record all restraint codes; note whether the fault is current or stored
- De-energise the system: ignition off, battery disconnected, wait the specified stand-down time
- Unclip the pillar trim and check that every yellow SRS connector is fully latched and free of corrosion
- Look for water tracks, damp foam or rust inside the pillar and fix the leak before the electrical repair
- Never put a plain ohmmeter across a squib; use an approved SRS load tool and measure the harness only
- Substitute the load tool at the curtain module connector; if the code changes to normal the inflator is the faulty part
- Repair the harness with SRS repair leads, then clear the code and confirm the circuit stays healthy over a road test