Code
B1231
ALFA ROMEO
B — Body
Crash detected
Views:
UK: 6
EN: 10
RU: 8
AI status
Completed
Completed
100%
Causes
- Actual crash/impact (airbags or pretensioners deployed)
- SRS control module recorded collision event (crash memory set)
- Faulty or damaged impact/acceleration sensor(s)
- Wiring harness damage, connector corrosion or short to power/ground to SRS sensors
- Water ingress or physical damage to SRS module or sensors
- Incorrect or incomplete repair after a collision (modules not cleared or replaced as required)
Symptoms
- Airbag / SRS warning lamp illuminated on dash
- Airbags and/or seatbelt pretensioners deployed or system inhibited
- SRS system disabled or vehicle shows multiple SRS-related fault codes
- Certain safety features locked out until SRS faults cleared and repairs completed
- Possible loss of subsystem communications (CAN) related to SRS module
What to check
- Perform a complete scan with an OEM-capable scan tool and read all SRS fault codes and freeze-frame data
- Check freeze-frame for vehicle speed, accelerator G-values, timestamp and voltage at time of event
- Inspect vehicle history for evidence of a collision or prior repairs
- Visually inspect SRS control module, impact sensors, pretensioners and harness routing for damage or water intrusion
- Check connector pins for corrosion, pushed-out terminals, or bent pins; verify proper mating
- Verify battery voltage and ground quality; check for intermittent power or low-voltage conditions
Signal parameters
- SRS crash flag / deployment flag
- Accelerometer (X/Y/Z) G-values at event
- Event timestamp / freeze-frame time
- Vehicle speed at time of event (if available)
- Ignition voltage during event
- Seatbelt pretensioner status (deployed/not deployed)
Diagnostic algorithm
- Connect OEM diagnostic tool and record all SRS and related module codes and freeze-frame data; do not clear codes yet.
- Confirm vehicle history: ask owner about any recent collisions, towing, or repair work that could affect SRS.
- Visually inspect impact sensors, connectors, wiring harnesses, SRS module and mounting for physical or water damage.
- Verify battery voltage and ground connections; ensure stable power during diagnostics.
- Use the OEM tool to read the SRS module crash memory and deployment flags to determine if deployment occurred.
- If crash data indicate deployment, follow manufacturer procedures: replace deployed airbags, pretensioners, and any required harnesses and the SRS module as specified.
- If no deployment but crash flag set, test individual impact sensors for correct resistance/signals and check wiring continuity to the SRS ECU; use oscilloscope where applicable.
- Repair any damaged wiring, connectors, or replace faulty sensors or SRS module as directed by service manual.
- After repairs and required part replacements, re-program/re-code and perform required SRS system initialization or learn procedures with OEM tool.
- Clear codes and perform functional tests and system self-tests; confirm no reoccurrence of B1231 or related faults.
- If fault persists, escalate to module bench testing or contact manufacturer technical support for module-level diagnostics.
Likely causes
- Vehicle was involved in an impact and crash data are stored in the SRS module
- One or more crash/occupant sensors failed or have open/shorted circuits
- SRS module flagged a crash state because of internal fault or corrupted memory
- Post-collision repairs left connectors, sensors or wiring damaged or disconnected
- Aftermarket equipment or previous incorrect module coding created a mismatch
Fault status
Status
Crash detected — SRS control module has recorded a collision event or collision-related state; inspection and corrective action required before restoring system to normal.
Repair difficulty: Hard
Diagnostic time: 2.0-5.0 hours
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