What does it mean?
B2123 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Ignition Run Control 1 Circuit High .
Symptoms
- Airbag warning lamp stays on and the passenger side protection is disabled
- Companion codes for the other satellite sensor or for the module supply
- Fault comes and goes when the passenger door is slammed or the seat is moved
- Passenger airbag status indicator behaving oddly
- Code returns immediately after clearing
- No warning at all until the lamp is noticed, so the system may have been down for some time
Likely causes
- Chafed wiring in the passenger B pillar, sill or under the carpet
- Water damage and corrosion at the passenger satellite sensor connector, common after a blocked drain or a leaking seal
- Satellite sensor failed internally and no longer communicating
- Damage from an aftermarket audio or alarm installation tapping into the sill loom
- Sensor mounting loose, or fitted with the wrong hardware after a repair
- Terminal backed out of the connector body, giving an intermittent connection
- Ignition run control circuit shorted to a battery feed on applications that use this definition
- Restraint control module internal fault, considered last
How to fix it
- Disconnect the battery and observe the manufacturer waiting time before touching restraint connectors
- Confirm the definition and the sensor location for this vehicle
- Lift the sill trim and carpet edge, look for pinch damage, moisture and aftermarket splices
- Dry and inspect the connector, checking for green terminals and a properly seated lock
- With the sensor unplugged, check the communication line for a short to ground and for continuity back to the module
- Substitute a known good sensor if the wiring measures correct
- Confirm the module supply voltage and ground quality
- Clear the code, complete a self test and road test to make sure the fault does not return