B1B79

Symptoms

• The SRS (airbag) warning light on the dashboard is on
• Error B1B79 stored in the ECU memory
• The passenger airbag may not activate in a collision.
• Passenger seat belt pretensioners can be disabled
• The passenger seat indicator may not work properly
• Possible false alarms or failures to activate security systems

Causes

• Broken or damaged sensor wire in the wiring harness
• Oxidation or corrosion of sensor connector contacts
• Loose or incorrect connector connection to the sensor
• Internal malfunction of the seat weight sensor (broken piezo element or resistive element)
• Damage to the electronic security control unit (SRS ECU)
• Short circuit in the sensor circuit to ground
• Sensor circuit fuse blown
• Incorrect SRS module calibration or programming

How to Fix

1. Connect an OBD-II scanner and remove a complete list of errors to analyze associated codes
2. Visually inspect the sensor wiring harness for damage, chafing or breaks.
3. Check the sensor connector for oxidation and corrosion; Clean contacts with alcohol if necessary
4. Disconnect the sensor connector and measure the voltage on the wires using a multimeter (should be 5 V on power, 0 V on ground)
5. Check sensor resistance according to manufacturer's specifications
6. Check the integrity of the wire from the sensor to the SRS control unit (this may require removing the seat upholstery)
7. If necessary, replace the passenger seat weight sensor with a new original component.
8. Reconnect the connector and make sure the connection is secure.
9. Erase the error from memory using a scanner and conduct a test run to check
10. Re-check the safety system by testing the airbags (according to the manufacturer's instructions)

Related codes

FAQ