• | 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 | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Side Impact Sensor Left Signal | -- | -- | B0077 | -- |
Side Impact Sensor Left Voltage | B0077 | B0077 | B0077 | B0077 |
Side Impact Sensor Right Signal | -- | -- | B0078 | -- |
Side Impact Sensor Right Voltage | B0078 | B0078 | B0078 | B0078 |
The inflatable restraint side impact sensor utilizes a unidirectional 2-wire circuit. The SIS modulates current on the interface to send ID, state of health (SOH), and deployment commands to the inflatable restraint sensing and diagnostic module (SDM). The SDM serves as a power source and a ground for the side impact 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 SIS continually communicates status messages to the SDM, which determines if a fault is present in the side impact sensor circuit. When a fault is detected, the SDM resets the side impact 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 side impact sensor being powered up. |
• | The SDM has not received a message from the side impact sensor for more than 375 milliseconds. |
• | The SDM has reset the side impact sensor twice without detecting a valid ID message. |
• | The SDM has received an ID message from the side impact sensor which does not match the ID stored in the SDM memory. |
• | The SDM has reset the side impact sensor twice without detecting a correct ID message. |
The SDM has received a NOK message from the side impact sensor.
• | The SDM requests the instrument panel cluster (IPC) to illuminate the AIR BAG indicator. |
• | The SIR system is disabled and no deployments are allowed. |
• | The condition responsible for setting the DTC no longer exists. |
• | A history DTC will clear once 100 malfunction-free ignition cycles have occurred |
SIR System Description and Operation
Control Module References for scan tool information
Important: When removing connectors, inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector.
• Side impact sensor • The SDM • Side impact sensor wiring harness connector • The SDM wiring harness connector
⇒ | If B0079, B0080, B0081, or B0082 is set, replace the appropriate inflatable restraint side impact sensor. |
⇒ | If less than the specified value, test the circuit for a short to ground. |
⇒ | If greater than the specified range, test the circuit for a short to voltage. |
⇒ | If greater than the specified range, test the circuit for a short to voltage. |
• | Left impact sensor terminal A and SDM terminal 40 |
• | Right impact sensor terminal A and SDM terminal 41 |
⇒ | If greater than the specified range, test the circuit for an open/high resistance. |
• | Left impact sensor terminal B and SDM terminal 42 |
• | Right impact sensor terminal B and SDM terminal 43 |
⇒ | If greater than the specified range, test the circuit for an open/high resistance. |
⇒ | If B0077 or B0078 is set, replace the SDM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for SDM replacement, setup, and programming |