Code
B1429
MITSUBISHI
B — Body
FR side impact sensor No COM.
Views:
UK: 7
EN: 11
RU: 14
AI status
Completed
Completed
100%
Causes
- Open or short in the sensor communication wiring
- Poor or corroded connector contact at the sensor or ECU
- No power or lost ground to the sensor
- Failed front-right side impact sensor (internal electronics)
- Faulty SRS/airbag control module (rare)
- Previous collision damage or improper repairs affecting sensor wiring
Symptoms
- Airbag / SRS warning lamp illuminated on instrument cluster
- SRS system disables some or all airbag deployment logic until fault is cleared
- Diagnostic trouble code B1429 stored in SRS ECU
- Possible intermittent SRS lamp if connection is intermittent
What to check
- Read and record all SRS codes and freeze-frame data with a capable OEM-level scan tool
- Visually inspect the FR side impact sensor, its mounting and connector for damage, corrosion or water ingress
- Inspect entire wiring route from the sensor to the SRS ECU for chafing, pinched areas (door hinge, seat tracks) and previous repair splice points
- Check connector pins for bending, corrosion, pushed-out pins or presence of moisture/contaminants
- Verify battery voltage and main power/ignition supply to the SRS system before doing resistance checks
- Perform wiggle test while monitoring live data / communication to see if fault appears/disappears
Signal parameters
- Sensor power supply: battery voltage present at sensor power pin with key ON (approx. 9–14 V)
- Sensor ground: continuity to chassis ground; low resistance (typically
- Communication: sensor should respond on vehicle safety bus (OEM SRS serial/communication or CAN/LIN) — diagnostic tool should show presence of sensor data/frames
- No communication condition: no packets or no sensor ID reported to SRS ECU when compared to known-good sensor/expected values
- Resistance checks: some sensors permit basic continuity or resistance checks of internal circuits — consult factory service data for correct pin values before measuring
Diagnostic algorithm
- Connect an OEM-capable SRS scan tool. Read and record all stored SRS codes and freeze-frame data; confirm B1429 is current or historic.
- Attempt to communicate with the FR side impact sensor via the scan tool. Note live data availability and any communication errors.
- Visually inspect the FR side impact sensor connector and wiring harness for damage, corrosion, pulled-out pins, or water intrusion. Repair any obvious issues.
- With ignition OFF, disconnect the battery per safety procedure for SRS work if you will be removing or replacing the sensor (follow manufacturer recommendations).
- With ignition ON (and SRS precautions observed), measure supply voltage at the sensor power pin and verify ground continuity to chassis. Compare to expected vehicle battery voltage.
- Check continuity between the sensor communication/power/ground pins and the SRS ECU pins. Look for opens, shorts to ground or battery, or high resistance connections.
- Perform a wiggle/stress test along the harness while monitoring live data to locate intermittent faults (doors, seat tracks, and under-seat routing are common failure points).
- If wiring and connectors are good, swap the FR side impact sensor with a known-good sensor (if available) or install a replacement sensor to confirm sensor failure.
- If replacing sensor does not clear the fault, test/inspect the SRS ECU communication circuits and grounds. Consult factory wiring diagrams and perform bench or module-level diagnostics as specified.
- After repairs, clear codes, perform any required SRS system initialization or calibration per manufacturer procedure, then re-scan and road test to confirm the repair.
Likely causes
- Damaged or disconnected sensor connector (moisture/corrosion)
- Broken wire or short between sensor and SRS ECU (pinched at door hinge or seat)
- Sensor lost supply voltage or ground
- Failed sensor electronics (internal open/short)
- SRS control module communication circuit fault (less likely)
Fault status
Status
No communication received from front-right side impact sensor. The SRS control unit cannot communicate with or detect the sensor on its assigned circuit/bus.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours
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