• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
Front End Sensor Left Signal Circuit | -- | -- | B0100 | -- | -- |
Front End Sensor Left Voltage Circuit | B0100 | B0100 | B0100 | B0100 | B0100 |
Front End Sensor Right Signal Circuit | -- | -- | B0103 | -- | -- |
Front End Sensor Right Voltage Circuit | B0103 | B0103 | B0103 | B0103 | B0103 |
The inflatable restraint front end sensor utilizes a unidirectional 2-wire circuit. The front end sensor 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 front end sensor. 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 front end sensor continually communicates status messages to the SDM, which determines if a fault is present in the front end sensor circuit. When a fault is detected, the SDM resets the front end sensor twice by removing and reapplying power to it. If the fault is still present, the SDM will set a DTC.
Ignition voltage is between 9-16 volts.
All of the following conditions exist for 2.5 seconds:
• | A valid ID message is not received within 5 seconds of the front end sensor being powered up. |
• | The SDM has not received a message from the front end sensor for more than 375 milliseconds. |
• | The SDM has reset the front end sensor twice without detecting a valid ID message. |
• | The SDM has received an ID message from the front end sensor, which does not match the ID stored in the SDM memory. |
• | The SDM has reset the front end sensor twice without detecting a correct ID message. |
The SDM has received a NOK message from the front end sensor.
• | The SDM commands the AIR BAG indicator ON via serial data communications. |
• | The SIR System is disabled and no deployments are allowed. |
• | The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used. |
• | A history DTC will clear once 255 malfunction-free ignition cycles have occurred. |
Important: When removing connectors inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector.
• The front end sensor • The SDM module • The front end sensor wiring harness connector • The SDM wiring harness connector
⇒ | If DTC B0101 or B0102 is set current replace the front end sensor 1/left. |
⇒ | If DTC B0104 or B0105 is set current replace the front end sensor 2/right. |
⇒ | If any of the above conditions are found make the appropriate repair. |
⇒ | If DTC B0100 was current replace the front end sensor 1. After replacement refer to Repair Verification. |
⇒ | If DTC B0103 was current replace the front end sensor 2. After replacement refer to Repair Verification. |
• | Control Module References for SDM replacement, setup, and programming |
Ignition ON, use the scan tool to clear the DTCs then recheck for DTCs. Verify no DTCs are set.
⇒ | If DTC B0100 or B0103 was current replace the SDM. |