B0077 Code: Meaning, Causes, and Symptoms | OBD2 Codes

B0077 – Left Front/Driver Side Impact Sensor Performance


B0077 Possible Symptoms


Air Bag Warning Light ON


B0077 Possible Causes


Faulty Left Front/Driver Side Impact Sensor (SIS),Left Front/Driver Side Impact Sensor (SIS) harness is open or shorted,Left Front/Driver Side Impact Sensor (SIS) circuit poor electrical connection,Faulty Inflatable Restraint Sensing and Diagnostic Module (SDM)


B0077 Description


The Inflatable Restraint Side Impact Sensor (SIS) utilizes a unidirectional 2-wire circuit. The SIS modulates current on the interface to send ID, State of Health, and deployment commands to the Inflatable Restraint Sensing and Diagnostic Module (SDM). The SDM serves as a power source and a ground for the SIS. When the ignition is turned on and input power from the SDM is first detected, the SIS responds by performing internal diagnostics and sending an ID to the SDM. The SDM considers the ID to be valid if the response time is less than 5 seconds. The SIS continually communicates status messages to the SDM, which determines if a fault is present in the SIS circuit. When a fault is detected, the SDM resets the SIS twice by removing and reapplying power. If the fault is still present, the SDM will set a Diagnostic Trouble Code (DTC).